APPENDIX F-I 

Delineation Reports

APPENDIX F-I.1

Death Valley 

Huffman-Broadway Group, Inc.

Environmental Consultants

Investigation of the Presence of Wetlands and

Other Waters of the United States 

DesertXpress Project 

HUC 8 Death Valley - Lower Amargosa Watershed

Draining to Badwater Basin

San Bernardino County, California

July 2010 

HBG

F-I.1-1
Prepared for

DesertXpress Enterprises, LLC

6750 Via Austi Parkway 

Suite 250 

Las Vegas, NV 89119 

By

Huffman-Broadway Group, Inc. 

828 Mission Avenue 

San Rafael, CA 94901 

F-I.1-2
TABLE OF CONTENTS

1.0 INTRODUCTION.......................................................................................................... 1

1.1 PROJECT PURPOSE AND SCOPE OF WORK ..................................................................................... 1

1.2 CONTACT INFORMATION .............................................................................................................. 2

1.3 STUDY AREA................................................................................................................................ 2

1.4 ENVIRONMENTAL SETTING ........................................................................................................... 2

1.4.1 Topography............................................................................................................................. 3

1.4.2 Land Use................................................................................................................................. 3

1.4.3 Geology and Soils................................................................................................................... 3

1.4.4 Biological Resources.............................................................................................................. 4

1.4.5 Climate ................................................................................................................................... 6

1.4.6 Hydrology ............................................................................................................................... 6

1.5 DISCLAIMER ................................................................................................................................. 7

2.0 REGULATORY FRAMEWORK................................................................................... 8

2.1 DEFINITION OF WETLANDS AND OTHER WATERS OF THE U.S....................................................... 8

2.2 LIMITS OF JURISDICTION............................................................................................................... 9

2.3 IDENTIFICATION OF ORDINARY HIGH WATER MARKS (OHWM).................................................. 9

2.4 WETLANDS DELINEATION CRITERIA ........................................................................................... 11

2.4.1 Wetland Hydrology............................................................................................................... 12

2.4.2 Hydric Soils.......................................................................................................................... 14

2.4.3 Prevalence of Wetland Vegetation........................................................................................ 17

3.0 DELINEATION METHOD ..........................................................................................20

3.1 OBJECTIVE AND ESTABLISHMENT OF STUDY AREA BOUNDARY ................................................. 20

3.2 STUDY AREA RECONNAISSANCE ................................................................................................ 20

3.3 WETLANDS IDENTIFICATION AND DELINEATION ......................................................................... 21

3.3.1 Dominance of Wetland Vegetation ....................................................................................... 21

3.3.2 Presence of Hydric Soil Indicators....................................................................................... 21

3.3.3 Presence of Wetland Hydrology Indicators.......................................................................... 21

3.4 IDENTIFICATION AND DELINEATION OF OTHER WATERS............................................................. 22

3.5 MAPPING.................................................................................................................................... 23

4.0 TECHNICAL FINDINGS ............................................................................................24

4.1 FIELD INDICATORS OF HYDRIC SOILS.......................................................................................... 24

4.2 FIELD INDICATORS OF WETLAND HYDROLOGY CONDITIONS ...................................................... 24

4.2.1 Field Indicators of Surface Flow.......................................................................................... 25

4.2.2 Landscape Features that Support Surface Flow................................................................... 26

4.2.3 Landscape Features with a Recognizable OHWM ............................................................... 27

4.3 FIELD INDICATORS OF WETLAND VEGETATION .......................................................................... 27

4.4. PRESENCE OF WETLAND VEGETATION WITHIN NATURAL AND MANMADE DRAINAGES .............. 28

5.0 AREAS POTENTIALLY SUBJECT TO JURISDICTION ..........................................29

5.1 WETLANDS................................................................................................................................. 29

5.2 OTHER WATERS OF THE U.S....................................................................................................... 29

6.0 CWA JURISDICTIONAL ANALYSIS ........................................................................30

6.1 REGULATORY BACKGROUND...................................................................................................... 30

6.2 REVIEW AREA ............................................................................................................................ 32

6.3 CWA ANALYSIS......................................................................................................................... 32

6.3.1 Are Jurisdictional Waters Present within the Study Area (Rapanos Guidance)?................. 32

6.3.2 Are There Isolated Waters within the Study Area?............................................................... 34

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6.4 ARE NON-JURISDICTIONAL WATERS PRESENT WITHIN THE STUDY AREA? ................................... 36

6.5 JURISDICTIONAL ANALYSIS SUMMARY ....................................................................................... 36

6.6 DISCLAIMER ............................................................................................................................... 38

7.0 REFERENCES...........................................................................................................39

LIST OF TABLES

Table 1a Potential Geomorphic Indicators of Ordinary High Water Marks for the 

Arid West

Table 1b Potential Vegetation Indicators of Ordinary High Water Marks for the 

Arid West

Table 2 Wetland Hydrology Indicators

Table 3 Wetland Hydrology Indicators for the Arid West

Table 4 Field Indicators of Hydric Soil Conditions

Table 5 Hydric Soil Indicators for the Arid West

Table 6 Summary of Process for Determining Jurisdiction Over Waters of the 

U.S. Under Section 404 of the Clean Water Act Following EPA and 

Corps Rapanos Guidance

Table 7 Summary of EPA and Corps Rapanos Analysis

Table 8 Interstate / Foreign Commerce Analysis

Table 9 Jurisdictional Analysis Summary

LIST OF EXHIBITS

Exhibit A Figures

Figure 1 DesertXpress Project Alignment Alternatives

Figure 2 Location of Alignment Alternatives Within HUC-8 Watershed

Figure 3 Location of Study Area

Figure 4 Location of Study Area Within HUC-8 / HUC-12 Watersheds

Figures 5-12 Typical Examples of Field Indicators of Active Surface Water Flow and 

Ordinary High Water Marks Found Within Ephemeral Drainages Occurring 

Within the DesertXpress Project Study Area.

Figures 13-19 Examples of Drainages Found Within HUC-8 Watershed

Exhibit B Field Data 

Exhibit B1 Required Corps Waters Data Summary Table

Exhibit B2 Field Data

Exhibit C Representative Areas Potentially Excluded from Corps Jurisdiction 

Based on Corps-EPA Rapanos Guidance, DesertXpress Project, 

HUC 8 Death Valley-Lower Amargosa Watershed Draining to 

Badwater Basin

Exhibit D Hydrology Maps for CWA Jurisdictional Analysis

This report should be cited as: Huffman-Broadway Group, Inc. 2010. Investigation of the Presence of 

Wetlands and Other Waters of the United States, DesertXpress Project, HUC 8 Death Valley - Lower 

Amargosa Watershed Draining to Badwater Basin, San Bernardino County, California. Prepared for 

DesertXpress Enterprises, LLC, Las Vegas, Nevada. July. 40 pp. plus Exhibits.

F-I.1-4
1.0 INTRODUCTION

1.1 Project Purpose and Scope of Work

DesertXpress Enterprises, LLC (DXE) is proposing to construct and operate a dedicated 

two-tracked high speed passenger railway and associated operations and maintenance 

facilities between Victorville, California, and Las Vegas, Nevada (DesertXpress Project; 

Exhibit A, Figure 1). A Draft Environmental Impact Statement was issued for the project 

in March of 2009 and the Final EIS is nearing completion. A Supplemental Draft EIS has 

been prepared and will be issued shortly to address certain modifications to the proposed 

alignment and station locations made by the Applicant, DXE, in response to various 

comments made on the Draft. The U.S. Department of Transportation, Federal Railroad 

Administration (FRA) is the lead agency responsible for preparing the project 

Environmental Impact Statement (EIS). 

In preparation for the permit phase of the project, DXE has retained Huffman-Broadway 

Group, Inc. (HBG) to investigate the presence of wetlands and other waters potentially 

subject to Corps and EPA regulation under Section 404 of the Clean Water Act (CWA) 

along the DesertXpress Project’s preferred and alternative alignments and study areas for 

the stations and ancillary facilities. 

For the purpose of the jurisdictional delineation study the proposed DesertXpress Project 

has been divided into six areas using the USGS HUC 8 1

This study was conducted in accordance with Code of Federal Regulations (CFR) 

definitions of jurisdictional waters, the Corps’ 1987 Wetlands Delineation Manual, the 

Corps’ 2008 Regional Supplement to the Corps of Engineers Wetland Delineation 

Manual: Arid West Region (Version 2.0), and supporting guidance documents. The 

remaining portions of Section 1.0 provide project contact information, describe the 

location of the Study Area and provide technical details regarding the general 

environmental conditions found within the Study Area, including relevant technical 

information from the Draft EIS regarding water resource data and biological and cultural 

resource information. Section 2.0 provides regulatory background information and 

level of watershed classification. 

The scope of this report is to evaluate the presence or absence of wetlands and waters 

potentially subject to Corps CWA jurisdiction within the proposed DesertXpress Project 

alignments and facilities located within the HUC 8 Death Valley - Lower Amargosa 

watershed, which drains to Badwater Basin (Exhibit A, Figure 2 and Exhibit D). 

Badwater Basin, an ephemeral dry lake with no hydrological surface water outlet, is in 

Death Valley, California, and is at the lowest elevation in the United States (- 282 feet 

msl). 

1

 HUC = U.S. Geological Survey (USGS) Hydrologic Unit Code. The Hydrologic Unit system is a standardized 

watershed classification system developed by USGS in the mid 1970s. Hydrologic units are watershed boundaries 

organized in a nested hierarchy by size. They range in size from national regions, to the smaller cataloging units 

(HUCs), which are roughly equivalent to local watershed.

F-I.1-5
details regarding the technical criteria and types of field indicators evaluated for during 

the study. Section 3.0 provides a detailed description of the methods used during this 

investigation. Section 4.0 provides a description of technical findings and Section 5.0 

describes the types of areas found that potentially may be subject to Corps CWA 

jurisdiction. Section 6.0 is a Clean Water Act jurisdictional analysis using the Rapanos 

Guidance.

HBG is seeking, on behalf of DXE, a Verified Jurisdictional Determination pursuant to 

applicable Corps guidance documents. 

1.2 Contact Information

Project Owner Contact Applicant’s Agent & Wetland 

Regulatory Scientist

DesertXpress Enterprises, LLC

6750 Via Austi Parkway 

Suite 250 

Las Vegas, NV 89119 

Contact: 

Tom Stone 

(702) 491-8940 

tstone@transmaxgroup.com 

Huffman-Broadway Group, Inc 

828 Mission Avenue 

San Rafael, California 94901 

Contact: 

Terry Huffman, Ph.D. 

(415) 925-2000 

thuffman@h-bgroup.com

1.3 Study Area

The Study Area for this investigation is defined as the area where potential ground 

disturbing components of the proposed project would occur based on the alternatives 

identified and analyzed in conjunction with the EIS and Supplemental EIS prepared for 

the DesertXpress Project. The Study Area encompasses the eastern portion of the 

DesertXpress Project route Segment 3 Alternative 3B from Halloran Summit to Mountain 

Pass in San Bernardino County, California (Exhibit A, Figure 3). This portion of 

DesertXpress Project Segment 3 Alternative 3B comprises approximately 15.1 miles 

within the I-15 right of way on the north side of the freeway. 

1.4 Environmental Setting 

The Study Area encompasses those portions of the proposed DesertXpress Project 

alignment alternative and facilities in and adjacent to the north freeway right of way that 

lie within the following five HUC-12 sub-watersheds (Exhibit A, Figure 4): 

 Halloran Summit

 Rock Tank 

 Pachalka Spring-Kingston Wash 

 Ord Tank 

 Piute Valley

F-I.1-6
These HUC-12 watersheds are at the southeast boundary of the larger (HUC-8) Death 

Valley-Lower Amargosa Watershed (HUC 18090203). Seasonal runoff from these HUC12 watersheds collects in Kingston Wash, just north of I-15 in the Shadow Valley. 

Kingston Wash flows to its confluence with Salt Creek; Salt Creek flows generally west 

and north to the Amargosa River west of the Salt Spring Hills and Little Dumont Dunes. 

Here, the Amargosa flows into Death Valley and terminates in Badwater Basin, an 

isolated dry lake that is the lowest point on the landscape. All these waters are 

ephemeral.

1.4.1 Topography

The study area is within the Mojave Desert Geomorphic Province. The Mojave Desert 

Geomorphic Province is characterized by mountain ranges and hills of moderate relief 

that are partially buried and separated by broad alluviated basins. 

Maximum elevations in the Study Area range from approximately 4,000 feet MSL at 

Halloran Summit at the west end of the Study Area to 4,730 feet MSL at Mountain Pass 

at the east end of the Study Area. Lowest elevation is approximately 3,700 feet MSL in 

the basin between the summits. 

1.4.2 Land Use

This section of the DesertXpress route falls within the I-15 transportation corridor. On 

the south side of I-15, BLM owns an approximately half-mile buffer strip, with Mojave 

National Preserve, a designated national park unit, adjacent to the south, except in the 

Mountain Pass area where BLM holds a larger area. 

On the north side of the freeway along most of this portion of the route, BLM is the 

landowner, with land designated as part of the Shadow Valley Desert Wildlife 

Management Area from near Halloran Springs Road in T15N, R10E eastward through 

Section 17, T16N, 13E. At Mountain Pass, Molycorp Minerals’ Mountain Pass Mine 

produces high quality rare earth oxides, including cerium, lanthanum, neodymium, 

praseodymium and europium, for clean energy technologies, advanced water filtration 

systems, and national defense on BLM land. 

1.4.3 Geology and Soils

Halloran Summit

The Halloran Summit area comprises a large body of Tertiary-Mesozoic age granitic rock 

(gr, TKq) that is overlain by younger Pleistocene age volcanic basalt flows (Qpv, Qeb). 

The granitic rock body is intruded into an older, Precambrian metamorphic rock unit 

composed of gneiss (epЄ, pЄg) on the west side of the Halloran Summit. Segment 3 

Alternative 3B is underlain by the gneissic rock and younger alluvium (Qal) on the west 

side of the summit. Younger alluvium is mapped at the Halloran Summit pass but is 

underlain at relatively shallow depth by granitic and/or volcanic rock. The inactive 

Halloran fault runs parallel to I-15 in this area. 

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Halloran Summit – Mountain Pass 

In the Shadow Valley between Halloran Summit and Mountain Pass, Segment 3 

Alternative 3B would be underlain by younger valley and fan alluvium (Qal). A small 

exposure of Paleozoic age dolomite (IP/ls, DЄg, DЄgb1) is on the southwest side of 

Shadow Valley, and younger lacustrine deposits (Ql) from the Valley Wells lake bed are 

on the valley bottom. Ascending from Shadow Valley up to Mountain Pass, the segment 

crosses Pliocene-Pleistocene non-marine sediments (Qc, Qoa) that are along the base of 

the Mescal Range and Clark Mountain Range that comprise the Mountain Pass area.

These geologic units and associated soils are described below:

Geologic Unit (Symbol[s]) Geologic Age Description - Soils

Younger alluvial valley and fan 

sediments (Qal) Holocene Unconsolidated valley alluvial deposits of silt, 

sand, and gravel; alluvial fan deposits.

Younger lacustrine deposits (Ql) Holocene Lake and playa sediments including clay, silt, 

and fine sand; Soda Lake bed sediments.

Older alluvial deposits (Qc, Qoa) Pleistocene And 

Plio-Pleistocene

Dissected alluvial gravel, sand, and silt; 

continental terrace deposits of gravel, sand, silt, 

and clay.

Marine sedimentary and metasedimentary rocks (CM)Paleozoic -

Mississippian

Limestone and dolomite; includes Monte Cristo 

limestone of Hewett, 1956.

Marine sedimentary and metasedimentary rocks (Ds, Dsi)Paleozoic –

Devonian

Sultan limestone of Hewett, 1956, including 

ironside Dolomite members.

Marine sedimentary and metasedimentary rocks (IP/ls, Dєg, Dєgu, 

Dєgb1) 

Paleozoic – 

Cambrian And 

Devonian

Dolomite and Limestone with thin interbedded 

Shale and Sandstone; Goodsprings Dolomite and 

Carbonate Rocks including Breccia of Hewett, 

1956.

Metamorphic rocks (epє, pєg, pєga, pєgc 

pєgb) Precambrian Undifferentiated injection gneiss, schist, granitic gneiss, granite augen gneiss complex.

Granitic rocks (pєgr) Precambrian

Undivided syenite, shonkite, granite stocks, and 

dikes, including carbonate veins and irregular 

bodies in Mountain Pass area.

1.4.4 Biological Resources

In the Shadow Valley between Halloran Summit and Mountain Pass, the Study Area 

crosses disturbed habitats, creosote bush scrub, and saltbush scrub. Joshua tree woodland 

vegetation occurs between 2,500 and 4,500 feet in areas that receive 6 to 15 inches of rain 

a year; it has been mapped within the DesertXpress route between Halloran summit and 

Cima Road and between Cima Road and Mountain Pass. Mesquite bosque habitat has 

been mapped at Mountain Pass. The entire Mojave Desert is potential desert tortoise 

habitat. The following is a list of biological resources in the Study Area.

F-I.1-8
Biological Resources in the Study Area & Vicinity

Biological Resource Federal/State/

BLM/HCPStatus Description Potential for Occurrence

Special-Status Plant Species

Rusby’s desert-mallow –/–/S/NE

One California Natural Diversity Data Base 

(CNDDB) occurrence 1.5 miles north of project 

study area at Kingston Wash.

Yes

Desert pincushion –/–/–/– CNDDB occurrences adjacent to alignment at 

Kingston Wash and at west end of Mountain Pass. Yes

Hairy erioneuron –/–/–/– 

One CNDDB occurrence approximately one mile 

south of project study area at west end of 

Mountain Pass.

Yes

Aven Nelson’s phacelia –/–/–/– One CNDDB occurrence adjacent to alignment at 

Mountain Pass. Yes

Scaly cloak fern –/–/–/NE

One CNDDB occurrence on southern edge of 

Clark Mountain north of alignment at Mountain 

Pass.

Yes

Mormon needle grass –/–/–/– CNDDB occurrences on southern edge of Clark 

Mountain north of alignment at Mountain Pass. Yes

Nine-awned pappus 

grass

–/–/–/NE

One CNDDB occurrence on southern edge of 

Clark Mountain north of alignment at Mountain 

Pass.

Yes

Wright’s bedstraw –/–/S/NE

One CNDDB occurrence on southern edge of 

Clark Mountain north of alignment at Mountain 

Pass.

Yes

Clark Mountain spurge –/–/–/– 

One CNDDB occurrence on southern edge of 

Clark Mountain north of alignment at Mountain 

Pass.

Yes

Gilman’s cymopterus –/–/–/NE

One CNDDB occurrence on southern edge of 

Clark Mountain north of alignment at Mountain 

Pass.

Yes

Sky-blue phacelia –/–/–/– 

One CNDDB occurrence on southern edge of 

Clark Mountain north of alignment at Mountain 

Pass.

Yes

Chamber’s physaria –/–/–/– 

One CNDDB occurrence on southern edge of 

Clark Mountain north of alignment at Mountain 

Pass.

Yes

Special-Status Wildlife Species

Saratoga Springs 

pupfish --/SSC/--/-- 

CNDDB occurrence within 10 miles of project 

study area. No suitable habitat in project study 

area.

No

Banded Gila Monster --/SSC/S/W, NE

No CNDDB occurrences within 10 miles of 

project study area. Suitable habitat occurs in 

rocky habitat 

Yes

Desert tortoise T/T/--/W, NE Desert tortoises observed during 2007 surveys. 

Suitable habitat occurs in washes crossed by I-15. Yes

F-I.1-9
Biological Resources in the Study Area & Vicinity

Biological Resource Federal/State/

BLM/HCPStatus Description Potential for Occurrence

Bendire’s thrasher --/SSC/S/W, NE Several CNDDB occurrences in project study area. 

Suitable habitat in Joshua tree woodland. Yes

Crissal thrasher --/SSC/--/NE

No CNDDB occurrences within 10 miles of 

project study area. Suitable habitat in larger 

washes.

Yes

Golden Eagle PR/SSC,FP/--/NE

No CNDDB occurrences within 10 miles of 

project study area. Suitable nesting habitat in 

rocky habitat 

Yes

Le Conte’s thrasher --/SSC/--/W, NE

No CNDDB occurrences within project study area. 

Suitable habitat throughout project study area in 

desert scrub communities.

Yes

Prairie falcon --/SSC/--/NE

No CNDDB occurrences within 10 miles of 

project study area. Suitable nesting habitat in 

rocky habitat. 

Yes

Western burrowing owl --/SSC/S/W, NE

No occurrences within 10 miles of project study 

area. Suitable habitat occurs throughout project 

study area in desert scrub and agricultural habitats.

Yes

Desert bighorn sheep --/ FP/S/W, NE

CNDDB records indicate suitable habitat within 

10 miles of project study area. Suitable habitat 

does occur within project study area.

Yes

Hoary bat --/SSC/--/-- 

One CNDDB occurrence within 10 miles of 

project study area. No suitable roosting habitat n 

project study area.

No

Townsend’s big-eared 

bat --/SSC/S/W, NE

One CNDDB occurrence within 10 miles of 

project study area. Suitable roosting habitat in 

project study area.

Yes

1.4.5 Climate

The Mojave Desert has an arid to semi-arid climate; the area is in the rain shadow of 

5,000 to 11,000-foot high mountains west of the area. About 2/3 of average annual 

precipitation occurs between November and March, when winter storms move east from 

the Pacific Ocean. Precipitation amounts are higher in the mountains, ranging from about 

4 inches annually in lower areas, with precipitation over 12 inches annually in the highest 

elevations. In the higher mountains, winter precipitation may occur as snow. 

Precipitation in the summer comes as short, intense, and localized thunderstorms; much 

of this rain is lost to evapotranspiration, particularly if the storm is a small one. The 

farther east in the Mojave, summer storms are more frequent, as they arrive from Arizona 

to the south. (NPS 1999). Annual precipitation ranges from 5 to 10 inches. 

1.4.6 Hydrology

Surface water

Ephemeral seasonal runoff from the HUC-12 watersheds in this portion of the 

DesertXpress route drain north to Kingston Wash just north of I-15 in the Shadow Valley. 

 These watersheds comprise a portion of the larger (HUC-8) Death Valley-Lower 

F-I.1-10
Amargosa Watershed (HUC 18090203). Kingston Wash flows to Salt Creek; Salt Creek 

flows generally west and north to the Amargosa River, and the Amargosa flows into 

Death Valley, terminating in Badwater Basin. 

Groundwater 

Upper Kingston Valley Groundwater Basin (DWR Basin 6-22) is bounded by the 

Mesquite Mountains on the north, the Ivanpah and Clark mountains on the east, the 

Shadow Mountains on the west, and Teutonia Peak on the south. The basin underlies a 

northwest-trending valley. Kingston Wash is in the northwest part of the basin at an 

elevation of approximately 3,000 feet msl. The principal water-bearing unit in the basin 

is Quaternary alluvium having a maximum thickness of at least 400 feet. Replenishment 

of the basin is chiefly from the percolation of runoff through alluvial fan deposits at the 

base of the Ivanpah and Clark mountains. Groundwater in the younger and underlying 

older alluvium moves northward towards Kingston Wash and probably discharges as 

subsurface outflow to the Valjean Valley 

1.5 Disclaimer 

Huffman-Broadway Group, Inc. has conducted a thorough historical review and site 

investigation and made a good-faith effort herein to thoroughly describe and document 

the presence of potential factors that the Corps may consider in determining jurisdiction 

under their CWA jurisdiction as part of the Corps jurisdictional verification / 

determination process, however, DXE reserves the right to challenge or seek revision to 

any areas over which the Corps may assert jurisdiction. 

F-I.1-11
2.0 REGULATORY FRAMEWORK

2.1 Definition of Wetlands and Other Waters of the U.S.

Section 404 of the Federal Clean Water Act authorizes the Corps to regulate activities 

that discharge dredged or fill material to wetlands and other waters of the United States. 

As described by EPA’s and the Corps’ regulations (40 CFR § 230.3(s) and 33 CFR § 

328.3(a), respectively), the term “waters of the United States" encompasses the following 

resources: 

(1) All waters which are currently used, or were used in the past, or may be 

susceptible to use in interstate or foreign commerce, including all waters 

which are subject to the ebb and flow of the tide; 

(2) All interstate waters including interstate wetlands; 

(3) All other waters such as intrastate lakes, rivers, streams (including 

intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie 

potholes, wet meadows, playa lakes, or natural ponds, the use, degradation 

or destruction of which could affect interstate or foreign commerce 

including any such waters: 

(i) Which are or could be used by interstate or foreign travelers for 

recreational or other purposes; or 

(ii) From which fish or shellfish are or could be taken and sold in 

interstate or foreign commerce; or 

(iii) Which are used or could be used for industrial purpose by industries 

in interstate commerce 

(4) All impoundments of waters otherwise defined as waters of the United 

States under the definition; 

(5) Tributaries of waters identified in paragraphs (a) (1) through (4) of this 

section; 

(6) The territorial seas; 

(7) Wetlands adjacent to waters (other than waters that are themselves 

wetlands) identified in paragraphs (a) (1) through (6) of this section. 

EPA and the Corps define wetlands as: 

...those areas that are inundated or saturated by surface or ground water at 

a frequency and duration sufficient to support, and that under normal 

circumstances do support, a prevalence of vegetation typically adapted for 

life in saturated soil conditions. Wetlands generally include swamps, 

marshes, bogs, and similar areas. (EPA regulations at 40 CFR § 230.3(t); 

Corps regulations at 33 CFR § 328.3(b)). 

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2.2 Limits of Jurisdiction 

The following provides the regulatory definitions and criteria followed in determining the 

geographic extent of potential EPA/Corps jurisdiction as applicable to inland waters. 

The geographic limits of relevant federal jurisdiction for non-tidal waters of the U.S. are 

defined as follows at 33 CFR § 328.4(c): 

Non-Tidal Waters of the United States: The limits of jurisdiction in non-tidal 

waters: 

(1) In the absence of adjacent wetlands, the jurisdiction extends to the 

ordinary high water mark.

(2) When adjacent wetlands are present, the jurisdiction extends beyond the 

ordinary high water mark to the limit of the adjacent wetlands. 

(3) When the water of the United States consists only of wetlands the 

jurisdiction extends to the limit of the wetland. 

The terms “adjacent” and “ordinary high water mark,” used in the above definition, are 

defined at 33 CFR § 328.3 as follows: 

The term adjacent means bordering, contiguous, or neighboring. 

Wetlands separated from other waters of the United States by man-made 

dikes or barriers, natural river berms, beach dunes and the like are 

“adjacent wetlands.” (33 CFR § 328.3(c)) 

The term ordinary high water mark means that line on the shore 

established by the fluctuations of water and indicated by physical 

characteristics such as clear, natural line impressed on the bank, shelving, 

changes in the character of soil, destruction of terrestrial vegetation, the 

presence of litter and debris, or other appropriate means that consider the 

characteristics of the surrounding areas. (33 CFR § 328.3(e)) 

A site must meet certain water, soil, and vegetation criteria to qualify as a jurisdictional 

wetland. The Corps’ 1987 Wetlands Delineation Manual and various regional 

supplements describe these criteria and the methods used to determine whether they are 

met and the geographic extent of wetland areas identified in the field. 

2.3 Identification of Ordinary High Water Marks (OHWM)

The Corps definition of Ordinary High Water Mark (OHWM) provides the criterion by 

which the OHWM line can be identified which consists of “that line on the shore 

established by fluctuations of water and indirect physical characteristics” (33 CFR § 

328.3(e)). The Corps has developed a delineation manual for the identification of 

OHWMs within the Arid West Region, entitled A Field Guide to the Identification of the 

Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United 

States, A Delineation Manual (Lichvar and McColley 2008). Tables 1a and 1b, below 

provide a summarized listing from the manual of indicators associated with areas that 

become flood or ponded, but are not dominated by wetland vegetation and the duration of 

F-I.1-13
flooding, ponding and/or near surface soil saturation (≤12 inches) is not sufficient to 

cause hydric soils to form or wetland hydrology conditions to occur. 

Table 1a. Potential Geomorphic Indicators of Ordinary High Water Marks for the 

Arid West *

Potential Geomorphic OHWM Indicators 

(A) Below OHW (B) At OHW (C) Above OHW

1. In-stream dunes

2. Crested ripples

3. Flaser bedding

4. Harrow marks

5. Gravel sheets to rippled 

sands 

6. Meander bars

7. Sand tongues

8. Muddy point bars

9. Long gravel bars

10. Cobble bars behind 

obstructions 

11. Scour holes downstream 

of obstructions

12. Obstacle marks

13. Stepped-bed morphology 

in gravel

14. Narrow berms and levees

15. Streaming lineations

16. Dessication / mud cracks

17. Armored mud balls

18. Knick Points

1. Valley flat

2. Active floodplain

3. Benches: low, mid, most prominent

4. Highest surface of channel bars

5. Top of point bars

6. Break in bank slope

7. Upper limit of sand-sized particles

8. Change in particle size distribution

9. Staining of rocks

10. Exposed root hairs below intact soil layer

11. Silt deposits

12. Litter (organic debris, small twigs and leaves)

13. Drift (organic debris, larger than twigs)

1. Desert pavement

2. Rock varnish

3. Clast weathering

4. Salt splitting

5. Carbonate etching

6. Depositional topography

7. Caliche rubble

8. Soil development

9. Surface color/tone

10. Drainage development

11. Surface relief

12. Surface rounding

* Adapted from A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West 

Region of the Western United States, A Delineation Manual (Lichvar and McColley 2008). 

F-I.1-14
Table 1b. Potential Vegetation Indicators of Ordinary High Water Marks for the 

Arid West *

Potential Vegetation OHWM Indicators 

(D) Below OHW (E) At OHW (F) Above OHW

Hydroriparian 

indicators 

1. Herbaceous marsh 

species

2. Pioneer tree seedlings

3. Sparse, low 

vegetation

4. Annual herbs, 

hydromesic ruderals

5. Perennial herbs, 

hydromesic clonals

1. Annual herbs, hydromesic 

ruderals 

2. Perennial herbs, 

hydromesic clonals

3. Pioneer tree seedlings

4. Pioneer tree saplings

1. Annual herbs, xeric 

ruderals 

2. Perennial herbs, non-clonal

3. Perennial herbs, clonal and 

non-clonal co-dominant 

4. Mature pioneer trees, no 

young trees

5. Mature pioneer trees 

w/upland species

6. Late-successional species

Mesoriparian 

indicators 

6. Pioneer tree seedlings

7. Sparse, low 

vegetation

8. Pioneer tree saplings

9. Xeroriparian species

5. Sparse, low vegetation 

Annual herbs, hydromesic

6. ruderals 

7. Perennial herbs, 

hydromesic clonals

8. Pioneer tree seedlings

9. Pioneer tree saplings

10. Xeroriparian species

11. Annual herbs, xeric 

ruderals 

7. Xeroriparian species

8. Annual herbs, xeric 

ruderals 

9. Perennial herbs, non-clonal

10. Perennial herbs, clonal and 

non-clonal codominent

11. Mature pioneer trees, no 

young trees 

12. Mature pioneer trees, xeric 

understory 

13. Mature pioneer trees 

w/upland species

14. Late-successional species

15. Upland species

Xeroriparian 

indicators 

10. Sparse, low 

vegetation

11. Xeroriparian species

12. Annual herbs, xeric 

ruderals

12. Sparse, low vegetation

13. Xeroriparian species

14. Annual herbs, xeric 

ruderals 

16. Annual herbs, xeric 

ruderals 

17. Mature pioneer trees 

w/upland species

18. Upland species

* Adapted from A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West 

Region of the Western United States, A Delineation Manual (Lichvar and McColley 2008). 

2.4 Wetlands Delineation Criteria

The Corps’ 1987 Wetlands Delineation Manual identifies the key diagnostic criteria for 

determining the presence of wetlands. These include: 

1. Wetland Hydrology: Inundation or saturation to the surface during the 

growing season. 

2. Hydric Soils: Soils classified as hydric or that possess characteristics 

associated with reducing soil conditions. 

3. Predominance of Wetland Vegetation: Vegetation classified as facultative, 

facultative wet, or obligate according to its tolerance of saturated (i.e., 

anaerobic) soil conditions. 

Specific criteria used to determine the presence or absence of wetland hydrology, soil, 

and vegetation conditions are described in the sections below. 

F-I.1-15
2.4.1 Wetland Hydrology

The 1987 Corps Manual states that wetland hydrology conditions occur when a “site is 

inundated either permanently or periodically at mean water depths less than or equal to 

6.6 feet, or the soil is saturated to the surface at some time during the growing season of 

the prevalent vegetation.” Whether a site meets either of these criteria is determined by 

the presence of diagnostic indicators of wetland hydrology, which include those listed in 

Table 2.

Table 2. Wetland Hydrology Indicators

(Based on 1987 Corps Manual and Corps Guidance Documents)

Primary Indicators Secondary Indicators

Watermarks Oxidized Rhizospheres Associated with 

Living Roots

Drift Lines Water-Stained Leaves

Water-Borne Sediment Deposits FAC-Neutral Test

Drainage Patterns Within Wetlands Local Soil Survey Data

A March 8, 1992, Corps memorandum entitled Clarification and Interpretation of the 

1987 Manual provides further clarification: 

Areas which are seasonally inundated and/or saturated to the surface for a 

consecutive number of days for more than 12.5 percent of the growing 

season are wetlands, provided the soil and vegetation parameters are met. 

Areas wet between 5 percent and 12.5 percent of the growing season in 

most years may or may not be wetlands. Sites saturated to the surface for 

less than 5 percent of the growing season are non-wetlands.

Wetland hydrology indicators have also been further defined and described in the 

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region (Version 2.0) (Corps 2008). These indicators are similar to the indicators listed 

above from the 1987 Corps Manual and are presented in Table 3. 

F-I.1-16
Table 3. Wetland Hydrology Indicators for the Arid West

(Based on Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region, Version 2.0)

Primary Indicators (any one indicator is 

sufficient to make a determination that 

wetland hydrology is present) 

Secondary Indicators (two or more 

indicators are required to make a 

determination that wetland hydrology is 

present) 

Group A – Observation of Surface Water or Saturated Soils

A1* – Surface Water X 

A2 – High Water Table X 

A3 – Saturation X 

Group B – Evidence of Recent Inundation

B1 – Water Marks X (Nonriverine) X (Riverine)

B2 – Sediment 

Deposits 

X (Nonriverine) X (Riverine)

B3 – Drift Deposits X (Nonriverine) X (Riverine)

B6 – Surface Soil 

Cracks X 

B7 – Inundation 

Visible on Aerial 

Imagery 

X 

B9 –Water-Stained 

Leaves X 

B10 – Drainage X 

B11 – Salt Crust X 

B12 – Biotic Crust X 

B13 – Aquatic 

Invertebrates X 

Group C – Evidence of Current or Recent Soil Saturation

C1 – Hydrogen Sulfide 

Odor X 

C2 – Dry-Season 

Water Table X 

C3 – Oxidized 

Rhizospheres 

along Living 

Roots 

X 

C4 – Presence of 

Reduced Iron X 

C6 – Recent Iron 

Reduction in 

Tilled Soils 

X 

C7 – Thin Muck 

Surface X 

C8 – Crayfish Burrows X 

F-I.1-17
Table 3. Wetland Hydrology Indicators for the Arid West

(Based on Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region, Version 2.0)

Primary Indicators (any one indicator is 

sufficient to make a determination that 

wetland hydrology is present) 

Secondary Indicators (two or more 

indicators are required to make a 

determination that wetland hydrology is 

present) 

C9 – Saturation Visible 

on Aerial Imagery X 

Group D – Evidence from Other Site Conditions or Data

D3 – Shallow Aquitard X 

D5 – FAC-Neutral Test X 

* Denotes number of wetland hydrology indicator described in detail in the Regional Supplement to the 

Corps of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0).

2.4.2 Hydric Soils

The 1987 Corps Manual states that the diagnostic environmental characteristics indicative

of wetland soil conditions are met when "soils are present and have been classified as 

hydric, or they possess characteristics that are associated with reducing soil conditions." 

According to the Manual, indicators of soils developed under reducing conditions may 

include: 

1. Organic soils (Histosols); 

2. Histic epipedons; 

3. Sulfidic material;

4. Aquic or peraquic moisture regime; 

5. Reducing soil conditions; 

6. Soil colors (chroma of 2 or less); 

7. Soil appearing on hydric soils list; and

8. Iron and manganese concretions. 

A February 20, 1992, Corps memorandum entitled Regional Interpretation of the 1987 

Manual states that the most recent version of National Technical Committee for Hydric 

Soils (NTCHS) hydric soil criteria will be used (to make hydric soil determinations). 

These soil criteria specify at least 15 consecutive days of saturation or 7 days of 

inundation (flooding or ponding) during the growing season in most years. 

The concept of hydric soils includes soils developed under sufficiently wet conditions to 

support the growth and regeneration of hydrophytic vegetation. Soils that are sufficiently 

wet because of artificial measures are included in the concept of hydric soils. Also, soils 

in which the hydrology has been artificially modified are hydric if the soil, in an unaltered 

state, was hydric. Some series, designated as hydric, have phases that are not hydric 

depending on water table, flooding, and ponding characteristics. As indicated above, like 

the NRCS, the Corps has typically accepted guidance for the identification of hydric soils 

developed by the National Technical Committee for Hydric Soils (NTCHS). The 

F-I.1-18
NTCHS, a working group organized by NRCS, has developed criteria for identifying and 

mapping hydric soils throughout the United States and defines a hydric soil as “a soil that 

formed under conditions of saturation, flooding or ponding long enough during the 

growing season to develop anaerobic conditions in the upper part [of the soil profile]” 

(http://soils.usda.gov/use/hydric/intro.html). The most recent (2000) version of the 

NTCHS hydric soils criteria identifies those soils that are likely to meet this definition. 

These criteria, which are accepted by most state and federal agencies, are as follows 

(http://soils.usda.gov/use/hydric/criteria.html):

1. All Histels except Folistels and Histosols except Folists, or

2. Soils in Aquic suborders, great groups, or subgroups, Albolls suborder, 

Historthels great group, Histoturbels great group, Andic, Vitrandic, and Pachic 

subgroups, or Cumulic subgroups that are: 

a. Somewhat poorly drained with a water table equal to 0.0 foot (ft) from 

the surface during the growing season, or 

b. poorly drained or very poorly drained and have either: 

(i.) water table equal to 0.0 ft during the growing season if textures 

are coarse sand, sand, or fine sand in all layers within 20 inches 

(in), or for other soils, 

(ii.) water table at less than or equal to 0.5 ft from the surface 

during the growing season if permeability is equal to or greater 

than 6.0 in/hour (h) in all layers within 20 in, or 

(iii.) water table at less than or equal to 1.0 ft from the surface 

during the growing season if permeability is less than 6.0 in/h 

in any layer within 20 in, or 

3. Soils that are frequently ponded for a long duration or a very long duration (7 

to 30 days) during the growing season, or 

4. Soils that are frequently flooded for a long duration or a very long duration (7 

to 30 days) during the growing season. 

On the basis of computer database searches for soils meeting the second criterion, NRCS 

has developed hydric soils lists for many parts of the country. Although they are useful 

for determining whether a particular soil series has the potential to support current hydric 

soil conditions

Field indicators of hydric soils are morphological properties known to be associated with 

soils that meet the definition of a hydric soil. Presence of one or more field indicators 

suggests that processes associated with hydric soil formation have taken place on the site 

being observed. The field indicators are essential for hydric soil identification because 

, caution should be used when using these lists for site-specific hydric soil 

determinations. Many soils on the lists have ranges in water table depths and other 

characteristics that allow them to be either hydric or nonhydric depending on landscape 

position and other site-specific factors (e.g., soil clay content, depth to bedrock). 

Accordingly, hydric soils lists are good ancillary tools to facilitate wetland 

determinations, but are not a substitute for onsite investigations. 

F-I.1-19
once formed, they persist in the soil during both wet and dry seasonal periods. However, 

few hydric soil indicators identify soils at a site as being currently hydric in accordance 

with the NTCHS hydric soils criteria described above. Field indicators of hydric soil 

conditions are listed in Table 4: 

Table 4. Field Indicators of Hydric Soil Conditions

(Based on 1987 Corps Manual and Corps Guidance Documents)

1. Indicators of Historical Hydric Soil 

Conditions: 2. Indicators of Current Hydric Soil Conditions:

a. Histosols

b. Histic epipedons;

c. Soil colors (e.g., gleyed or low-chroma colors, 

soils with bright mottles (Redoximorphic 

features) and/or depleted soil matrix 

d. High organic content in surface of sandy soils

e. Organic streaking in sandy soils 

f. Iron and manganese concretions 

g. Soil listed on county hydric soils list

a. Aquic or peraquic moisture regime (inundation 

and/or soil saturation for ≥7 continuous days)

b. Reducing soil conditions (inundation and/or soil 

saturation for ≥ 7 continuous days)

c. Sulfidic material (rotten egg smell)

The presence of one or more of the field indicators in “1 a, b, c, and/or d” above suggests 

that historical processes associated with hydric soil development have taken place at a 

given site. These indicators are useful in determining if soils at a site were historically 

formed under hydric soil conditions because the indicators persist in soils during both wet 

and dry periods and may remain for decades and even centuries after changes in site 

conditions occur that inhibit subsequent wetland development, such as the elimination of 

wetland hydrology (NRCS 1995). However, only the presence of field indicators “2 a, b, 

and/or c” confirms that hydric soils occur at a site during the period of observation. 

Hydric soil indicators have also been further defined and described in the Regional 

Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region 

(Version 2.0) (Corps 2008). These indicators are similar to those listed above from the 

1987 Corps Manual and are presented below in Table 5. 

F-I.1-20
Table 5. Hydric Soil Indicators for the Arid West

(Based on Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region, 

Version 2.0)

Hydric Soil Indicators Hydric Soil Indicators 

All Soils Sandy Soils Loamy & Clayey Soils for Problem Soils**

A1* – Histosol S1 – Sandy Mucky 

Mineral

F1 – Loamy Mucky 

Mineral A9 – 1 cm Muck

A2 – Histic Epipedon S4 – Sandy Gleyed 

Matrix

F2 – Loamy Gleyed 

Matrix A10 – 2 cm Muck

A3 – Black Histic S5 – Sandy Redox F3 – Depleted Matrix F18 – Reduced Vertic

A4 – Hydrogen Sulfide S6 – Stripped Matrix F6 – Redox Dark Surface TF2 – Red Parent 

Material

A5 – Stratified Layers -- F7 – Depleted Dark 

Surface

Other (See Section 5 of 

the Regional Supplement, 

Version 2.0)--

A9 – 1 cm Muck -- F8 – Redox Depressions --

A11 – Depleted Below 

Dark Surface

-- F9 – Vernal Pools --

A12 – Thick Dark 

Surface

-- -- --

* Denotes number of hydric soil indicator described in detail in Regional Supplement to the Corps of 

Engineers Wetland Delineation Manual: Arid West Region (Version 2.0). 

** Indicators of hydrophytic vegetation and wetland hydrology must be present.

It should also be noted for problematic areas that the 2008 Corps Regional Supplement 

specifies 14 days continuous ponding as an acceptable indicator of problematic hydric 

soils (USACE 2008, p. 101). 

2.4.3 Prevalence of Wetland Vegetation

Species Classifications 

Species classifications (e.g., tolerance of anaerobic soil conditions) are determined by 

consulting the National List of Plant Species that Occur in Wetlands (Reed 1988) and the 

relevant regional lists, which are published by FWS’ National Wetlands Inventory (NWI). 

Regional Interagency Review Panels develop the lists by determining species’ estimated 

probability of occurrence in wetlands vs. non-wetlands. Classifications are made by 

unanimous agreement of the Panel. If the Panel is unable to reach a unanimous decision 

on the status of a species, “no agreement” (NA) is recorded. If insufficient information 

exists to determine the status of a species, “no indicator” (NI) is recorded. Species that 

are not included in the NWI list are assigned a “not listed” (NL) designation in this report. 

F-I.1-21
The resulting NWI lists include plants that grow in a range of soil conditions from 

permanently wet to dry. Species are divided into the following “indicator categories:”

1. “Obligate wetland” (OBL) species, which, under natural conditions, occur 

almost always in wetlands (estimated probability >99 percent);

2. “Facultative wetland” (FACW) species, which usually occur in wetlands 

(estimated probability 67 – 99 percent), but are occasionally found in nonwetlands;

3. “Facultative” (FAC) species, which are equally likely to occur in wetlands 

or non-wetlands (estimated probability 34 – 66 percent); 

4. “Facultative upland” (FACU) species, which sometimes occur in wetlands 

(estimated probability 1 – 33 percent), but more often occur in nonwetlands; and

5. “Obligate upland” (UPL) species, which occur in wetlands in other 

regions, but, under natural conditions, occur almost always in non-wetlands 

in the region specified (estimated probability >99 percent). 

Species that have an indicator status of OBL, FACW, and FAC are typically considered 

to be adapted for life in anaerobic soil conditions (Corps 1987) and are used as evidence 

of hydrophytic vegetation when they dominate plant community composition or cover. 

Despite widespread use of the lists for wetland delineations, it is important to note that 

wetland indicator species assignments are not based on the results of a statistical analysis 

of species occurrence. The indicator assignments are approximations of wetland affinity 

based on a synthesis of submitted review comments, published botanical literature, and 

the field experience of the members of the Interagency Review Panel. For this reason and 

because many plants have properties that enable them to occur in a range of microhabitats 

(i.e., wetlands and non-wetlands), the presence of wetland indicator species is not 

unequivocal evidence of the presence of wetland hydrology and hydric soils. A positive 

indicator or indicators of wetlands should be emphasized, such as an assemblage of plants 

that can only be considered “hydrophytes” when they are growing in water or partly 

drained hydric soils (not effectively drained hydric soils) (Corps 1987). From the FWS 

perspective, all species on the NWI plant lists are hydrophytes at one time or another and 

the wetland indicator status (OBL, FACW, FAC, or FACU) reflects the likelihood that a 

given individual of a species is a hydrophyte or a certain population of these plants is 

hydrophytic. While OBL and FACW species are the most reliable plant indicators of 

wetlands, FAC and FACU species also contain populations of hydrophytes (Tiner 2006). 

For the reasons stated above, the 1987 Corps Manual does not solely rely on the presence 

of hydrophytic vegetation to make wetland determinations. 

Hydrophytic Vegetation Definitions 

The Corps’ 1987 Manual states that the wetland vegetation conditions are met when the 

prevalent vegetation (i.e., more than 50 percent of vegetation cover or tree basal area) 

consists of macrophytes that are typically adapted to sites having wetland hydrologic and 

soil conditions (e.g., periodic or continuous inundation or soil saturation). Hydrophytic 

vegetation is defined as “plant life growing in water or on a substrate that is at least 

F-I.1-22
periodically deficient in oxygen as a result of excessive water content” (Cowardin et al. 

1979). Hydrophytic vegetative species, due to morphological, physiological, and/or 

reproductive adaptation(s), have the ability to grow, effectively compete, reproduce, 

and/or persist in anaerobic soil conditions. Positive indicators of the presence of 

hydrophytic vegetation include: 

1. More than 50 percent of the dominant species are rated as Obligate ("OBL"), 

Facultative Wet ("FACW"), or Facultative ("FAC") on lists of plant species 

that occur in wetlands (see Reed 1988 for California); 

2. Visual observations of plant species growing in sites of prolonged inundation 

or soil saturation; and 

3. Reports in the technical literature indicating the prevalent vegetation is 

commonly found in saturated soils. 

Hydrophytic vegetation indicators have been further defined and described in the 

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West 

Region (Version 2.0) (Corps 2008). These indicators include: 

1. Dominance Test

2.

. More than 50 percent of the dominant plant species across 

all strata are rated OBL, FACW, or FAC. 

Prevalence Index

3.

. The prevalence index is 3.0 or less with indicators of 

hydric soils and wetland hydrology being present. 

Morphological Adaptations. The plant community passes either the 

dominance test or the prevalence index after reconsideration of the indicator 

status of certain plant species that exhibit morphological adaptations for life in 

wetlands. 

F-I.1-23
3.0 DELINEATION METHOD

This study was conducted in accordance with Code of Federal Regulations (CFR) 

definitions of jurisdictional waters, the Corps’ 1987 Wetlands Delineation Manual, the 

Corps’ 2008 Regional Supplement to the Corps of Engineers Wetland Delineation 

Manual: Arid West Region (Version 2.0), A Field Guide to the Identification of the

Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United 

States, A Delineation Manual, and supporting guidance documents. The following 

provides an overview of the objective of the delineation approach, how the Study Area is 

defined, and the methods used to identify and map (delineate) areas potentially subject to 

Corps jurisdiction under Section 404 of the CWA. 

3.1 Objective and Establishment of Study Area Boundary

The objective of this investigation is to identify and map areas potentially meeting the 

Clean Water Act definition of wetlands and Other Waters of the United States within the 

potential impact footprint of the DesertXpress Project. This impact footprint, which is 

encompassed within the Study Area, includes the proposed alignment and any alternative 

alignment and support facilities such as passenger stations and operations and 

maintenance facilities (e.g., maintenance yard, power substations, and transmission lines). 

 Temporary construction areas for equipment and materials laydown, new access roads, 

and borrow areas are also included within the Study Area. The boundary of the Study 

Area also represents a slightly larger area (increased alignment and facility ROW width 

by an average of 200 feet) to accommodate potential minor changes in the impact 

footprint. 

3.2 Study Area Reconnaissance

Prior to initiating detailed field survey work, existing land forms within the Study Area 

that may potentially contain wetlands or other waters of the United States were identified 

by conducting vehicle and pedestrian on-site reconnaissance inspections during the month 

of April 2010 in conjunction with review of the following information: 

• Aerial photography and satellite imagery of the area;

• USGS topographic mapping; 

• NRCS soils mapping; 

• Engineer scale topographic mapping of segment alternatives

• USGS National Hydrology Dataset; and

• Preliminary level vegetation mapping and wetland / OHWM data collection 

efforts conducted during February and March 2008 and September and October 

2009 as part of an on-going Federal EIS process by the FRA’s EIS contractor. 

The above efforts led to the development, in coordination with Corps regulatory staff, and 

use of the project-specific methods described below. 

F-I.1-24
3.3 Wetlands Identification and Delineation

Field surveys designed to identify the presence or absence of field indicators of wetland 

vegetation, soils and hydrology conditions were conducted within low-lying landscape 

features where wetlands could potentially occur. These field surveys were conducted 

during the months of April, May, and June 2010 after the detailed methodology was 

reviewed and approved by Corps staff during May 2010. 

3.3.1 Dominance of Wetland Vegetation 

Presence or absence of a dominance of wetland vegetation / hydrophytes within the Study 

Area was evaluated using the methodology described in Sections 2.2 and 2.4.3. Indicator 

status of plants was confirmed by referring to the National List of Plant Species that 

Occur in Wetlands: 1988 National Summary (Reed). Plant cover data were collected for 

individual species associated within and immediately adjacent to the landscape features 

identified during the site reconnaissance survey as having the potential to meet the Corps’ 

technical criteria for wetlands. Plant cover was visually estimated within 3-foot diameter 

plots at each soil sample location described below and was recorded on a Corps Wetland 

Determination Data Form – Arid West Region. Copies of completed data forms are 

provided in Exhibit B2. Subsequently, field data were analyzed to assess whether 

50 percent or greater of the dominant species within the area sampled are hydrophytes. 

Sites that are depressional landforms that do not have a dominance of wetland vegetation 

forming at least 5 percent cover were not considered to be dominated by hydrophytes and 

were classified as a potential “other water of the United States” following the 

methodology described in Section 3.4, below, except if conditions for problematic 

vegetation were met as described in the Corps’ 2008 Regional Supplement to the Corps of 

Engineers Wetland Delineation Manual: Arid West Region (Version 2.0). 

3.3.2 Presence of Hydric Soil Indicators

The presence or absence of hydric soil field indicators was evaluated following the 

methodology described in Section 2.3.2 using the Regional Supplement to the Corps of 

Engineers Wetland Delineation Manual: Arid West Region (Corps 2008). At each 

potential wetland sampling location within the Study Area, hand-dug soil pits were 

excavated to a minimum of 20 inches or until a limiting layer or standing water is

reached. The presence or absence of hydric soil indicators found at each soil pit location 

was recorded on a Corps Wetland Determination Data Form – Arid West Region. Copies 

of completed data forms are provided in Exhibit B. For sampling locations where the 

possibility of problematic hydric soils is found, procedures for the identification of 

problematic hydric soils as defined by the above described publication were followed. 

3.3.3 Presence of Wetland Hydrology Indicators 

The presence or absence of wetland hydrology field indicators were assessed following 

the methodology described in Section 2.3.1 using the Regional Supplement to the Corps 

of Engineers Wetland Delineation Manual: Arid West Region (Version 2.0) (Corps 

2008). The presence or absence of wetland hydrology indicators at each soil pit location 

was recorded on a Corps Wetland Determination Data Form – Arid West Region. Copies 

of completed data forms are provided in Exhibit B. For sampling locations where the 

F-I.1-25
possibility of problematic hydrology indicators was found, procedures for the 

identification of problematic hydrology indicators, as defined by the above-described 

publication, were followed. 

3.4 Identification and Delineation of Other Waters

Field surveys designed to identify the presence or absence of field indicators of an 

ordinary high water mark (OHWM) were conducted within low-lying landscape features 

where other waters of the United States could potentially occur. These field surveys were 

conducted during the months of April, May, and June 2010. 

HBG identified drainages within each watershed that potentially met the Corps technical 

criteria for Other Waters of the United States (presence of field indicators of active 

surface water flow and associated Ordinary High Water Mark [OHWM]) using the 

following approach based on A Field Guide to the Identification of the Ordinary High 

Water Mark (OHWM) in the Arid West Region of the Western United States, A 

Delineation Manual. 

Initial efforts involved identification of all drainages within the Study Area having the 

potential for active surface flow. This was accomplished through field reconnaissance 

and imagery interpretation. Detailed sampling was then conducted to identify and 

delineated active drainages with an OHWM. This was accomplished by randomly 

sampling the identified drainages in a stratified manner by geographically dividing the 

Study Area into HUC 12 watershed units. 

Field sampling within each HUC 12 watershed consisted of gathering OHWM data, 

including the measured width of the OHWM, for 3 to 5 main drainages (> 3 feet), if 

present, selected at random; and 6 to 10 (depending on watershed size) random samples 

of minor drainages (≤ 3 feet), if present. Each of the HCC 12 watersheds located within 

the Study Area was divided into approximate thirds. Then a minimum of, one major 

drainage and two minor drainages, if present, were sampled within each third of a 

watershed. Where the length of the watershed along the proposed DesertXpress Project 

alignment alternative was less than 5 miles, the watershed was divided into approximate 

halves, instead. If the minor drainages (≤ 3 feet) occurring within each one-third 

watershed varied in OHWM width by more than 33 percent, sampling was increased in 

that third of the watershed. 

Drainage data for each of the watershed drainages sampled was collected on a 

standardized field data sheet (Exhibit B). Exhibit A, Figures 5-12 provide examples of 

the types of field indicators observed within various drainages located along the 

DesertXpress Project alternative alignments. Each field sampling point was 

memorialized using a handheld GPS unit with submeter accuracy. Where stormwater 

flows originated upslope of the side of I-15 opposite the alignment, those drainages were 

hydrologically cut off by the freeway during construction and channeled into detention 

basins and / or manmade drainages on that side of I-15. As a consequence, drainages on 

the proposed alignment side of I-15 were hydrologically cut off from their sources and no 

F-I.1-26
longer technically meet the Corps OHWM criterion. This condition was noted on the 

field data sheets. Detailed OHWM indicator data for these historical drainage features 

was not collected. 

All drainage data (field and photointerpreted drainage data) are summarized by HUC 12 

watershed on the required LA District Excel JD Summary Data Sheet (see Exhibit B). 

Widths for active drainages identified through photointerpretation are based on an 

average width calculated from field data. The length of each drainage is based on 

photointerpretation. Standardized field data sheets, Corps Summary Data Sheets and 

representative photographs of various drainage features, and are provided in Exhibit B. 

The field data collected from each watershed was used to aid in the imagery interpretation 

process described in Section 3.5, below. 

3.5 Mapping

Wetland indicator data sample locations and the locations of areas identified during field 

surveys that are potentially Other Waters of the United States due to the presence of an 

OHWM were mapped using a hand-held Trimble XT global positioning system (GPS) 

unit with sub-meter accuracy. This GPS data was incorporated into a Geographic 

Information System (GIS) and geo-referenced in overlay fashion onto digital 

orthorectified satellite imagery and/or high resolution aerial photograph depending on 

availability. Overlays were used to assist in analysis, identification, and digitization of 

the location and geographic extent of areas that could potentially qualify as waters of the 

United States. The imagery interpretation process involved the combined use of available 

imagery, field data, engineer level topographic mapping, field verification of mapped 

features and best professional judgment to map the geographic extent of areas potentially 

subject to Corps CWA jurisdiction. Exhibit C presents representative detailed mapping 

within the Study Area with field sampling points and delineated active linear drainage 

features with labeling indicating their average OHWM width overlaid onto orthorectified 

digital imagery. Based on guidance received from Corps staff, only representative 

ephemeral drainages were mapped within a watershed that drains to an isolated dry lake 

that has no surface water drainage outlet. Resulting mapping depicts representative 

ephemeral drainages within the Study Area and the surface water flow path from the 

Study Area to the isolated dry lake. 

F-I.1-27
4.0 TECHNICAL FINDINGS

The following sections describe the landscape features and field indicators found within 

the Study Area that provide a technical basis for (a) determining the presence or absence 

of a potential water of the United States; and (b) defining the geographic extent of any 

potential water of the United States identified. Two types of landscape features were 

found that potentially contain waters of the United States. These include: 

1. Natural drainages

2. Manmade drainages

4.1 Field Indicators of Hydric Soils

Based on field observations within the Study Area soil indicators were not found that 

meet the hydric soils criteria defined by current Corps’ regulatory guidance, including the 

2008 Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid 

West Region (Version 2.0). On site observations of surface conditions, including road 

and channel bank cuts and interpretation of aerial photography revealed two primary soil 

types, desert pavement and more active wash sediments. On site examination revealed 

that soils or substrates within both natural drainages and manmade drainages consist of 

alluvial materials primarily made up of sorted sands and gravel, and are well drained, 

ranging from moderately well drained to excessively well drained.

4.2 Field Indicators of Wetland Hydrology Conditions

Based on field observations within the Study Area wetland hydrology indicators were not

found that meet the wetland hydrology criteria defined by current Corps’ regulatory 

guidance, including the 2008 Regional Supplement to the Corps of Engineers Wetland 

Delineation Manual: Arid West Region (Version 2.0). On site observations revealed 

evidence of flooding within the low-lying natural and manmade drainages. These 

observations also showed that there was no evidence of ponding and soil saturation for 

long to very long periods of time. The lack of ponding and soil saturation conditions 

meeting the wetland hydrology criteria is a direct result of the moderately well drained to 

excessively well drained alluvial soils. 

Although wetland hydrology conditions were not found within the Study Area, the field 

indicators of active surface water flow or flooding found within natural and manmade

drainages were sufficient enough to form Ordinary High Water Marks (OHWM). As 

indicated in Section 2.0, an OHWM provides a technical basis for (a) determining the 

presence a potential water of the United States; and (b) defining the geographic extent of 

potential water of the United States. 

The natural and manmade drainages within the Study Area found with an OHWM 

exhibited the following characteristics which are discussed in detail in the following 

subsections: 

F-I.1-28
1. Identifiable field indicators of surface flow 

2. Identifiable landscape features that supports surface flow 

3. Identifiable landscape features with a recognizable OHWM 

Exhibit A, Figures 5-12 provides typical examples of field indicators of active surface 

water flow and OHWMs found within ephemeral drainages occurring within the 

DesertXpress Project Study Area. Exhibit A, Figures 13-19 provide photographs of 

various types of drainages observed within the HUC 8 Death Valley - Lower Amargosa 

watershed.

4.2.1 Field Indicators of Surface Flow

Review of topographic mapping (USGS and Engineer scale) and imagery of the Study 

Area provided visual indication of the presence of curvilinear depressional land surface 

features where focused surface water flow could potentially be directed. Linear drainage 

features associated with road drainage and flood control were also found. Field 

investigations confirmed the presence of surface flow within a number of these channels 

or drainages while others lacked evidence / field indicators of active ephemeral surface 

water flow. No drainages were found to contain evidence of perennial or intermittent 

surface water flow, and no evidence of subsurface flow was found in the form of spring 

discharges, artesian flows or indicia of a high groundwater table. Observation of active 

natural and manmade ephemeral drainages revealed evidence of surface water / 

hydrologic connectivity with other active drainages within and outside the Study Area. 

These ephemeral drainages are locally referred to as “desert dry washes.” The manmade 

drainages served to redirect surface flow from altered natural drainages. Indicators of 

drainages having active surface water flow paths included (1) water marks defined by 

linear deposits of fine grained sediment, minerals and/or plant debris; (2) bank scour, 

erosion and/or shelving; (3) deposits of sorted alluvial materials; and (4) flow deposited 

woody and soft tissue plant debris (Exhibit B2). 

Flow-deposited woody and soft tissue plant debris were typically absent in drainages that 

did not have active surface flow. If woody debris was present, the pieces observed were 

relatively thick (i.e., greater that 1⁄4 inch) weathered limb or root material or milled posts 

or lumber. The wood pieces found were randomly placed and were not part of a 

collective flow line of deposited woody and/or soft tissue plant debris, which would be 

indicative of an active channel. The historical drainages were found to possess one or 

more of the same type of indicators found in active drainages, but the indicators found 

were considerably weathered. Surface flow indicators such as bank scour, erosion and 

shelving areas had rounded edges in contrast to those found in active drainages having 

angular edges. Water marks defined by linear deposits of fine grained sediment and 

minerals, and sorted alluvial materials such as gravels, cobbles and boulders were etched 

or varnished from weathering. The historical drainages were found to consist of the 

historical remains of channel drainages that were abandoned due to upslope changes in 

drainage due to either channel down-cutting or the channel becoming abandoned as the 

surface drainage became redirected or changed course due to deposition of alluvial 

material damming the channel flow path. The historical drainages were found to lack 

F-I.1-29
indicators of active flow. 

Surface water flow patterns were also found within various portions of the landscape that 

were relatively flat. These surface flow areas were defined by flow-deposited fine 

grained sediment or soft tissue plant debris. The visible surface flow pattern at these 

locations would continue for several feet then disappear either on a relatively flat soil 

surface or localized depression.

Based on the above technical findings and as documented in Exhibits B and C, drainages 

were found with indicators of active surface water flows within the Study Area. 

4.2.2 Landscape Features that Support Surface Flow

Detailed field surveys identified land surface features that have the potential to convey 

surface flows. These features included a bed or channel and abutting banks. These 

physical features were found associated with both active flow areas and historical 

drainages. These drainage types can be summarized as follows:

1. Active drainage channel and abutting banks containing evidence of recent surface 

flows as indicated by the presence of unweathered sediment material (sand, 

gravel, cobbles, etc.) with unweathered surfaces, and the presence of flow 

deposited woody debris and/or soft tissue plant debris. 

2. Active drainage channel and abutting banks containing evidence of historical 

surface flows as indicated by the presence of unweathered sediment material 

(sand, gravel, cobbles, etc.) with unweathered surfaces, but lacked the presence of 

flow deposited woody debris and/or soft tissue plant debris. 

3. Historical drainage channels and abutting banks having no evidence of recent 

surface flow as indicated by weathered sedimentary gravel, cobbles, boulders, 

erosional or depositional deposits, and the lack of flow deposited woody debris 

and/ or soft tissue plant debris. 

The frequency interval of flow events within drainages with observable plant debris (1 

above) and unweathered sediment material is estimated to be within the 1 to 15 year 

range. Strojan, et al. (1987) found that surface litter decomposition rates for creosote 

bush and burro bush in the Mojave Desert were 42.5% and 58.4%, respectively over a 54 

week period of study. Kemp, et al. (2003) reported a similar one year decomposition rate 

for creosote bush and a 74% loss within a 41 month period. This lends support to 

qualitative observations made by one of the preparers of this report, Dr. Terry Huffman, 

who has observed over 20 + years of delineating wetlands within arid environments that 

soft plant tissue (i.e., pieces of plant leaves and thin bark) will decompose in arid 

drainage environments within a 2 to 3 year period. In addition, field observations over 

these years indicated that small woody stems (<1/4 inch) decompose over many more 

years, perhaps 10 + years. For older drainages where the surfaces of the sediment 

material (e.g., sand, gravel, cobbles, etc.) is no longer smoothed by the interaction of 

surface water flow and transport, but weathered, and lacks flow deposited woody and thin 

tissue plant debris, the frequency interval likely ranges to well over a decade in shallower 

F-I.1-30
channels to prehistoric times for deeply incised channels (i.e., > 6 feet in desert pavement 

areas). 

The land surface of the Study Area is characterized by the presence of active and inactive 

alluvial fan systems. Ephemeral drainage channels are found on both types of these 

alluvial fan types. The majority of the ephemeral channels supporting active surface 

water flow were narrow, with an average width of less than 3 feet. Active alluvial fans 

were characterized by sandy soils, a uniform vegetation type, and evidence by surface 

flow patterns indicative of surface water sheetflow. Narrow channels within these areas 

were both weakly expressed and discontinuous. This discontinuity indicated that new 

channels could be formed with each major flood event resulting in the current channels 

being bypassed and blocked off. Channels >3 feet wide were also found. These channels 

were considerably deeper that the narrow channels found and were less common when 

considering the landscape as a whole in relationship to the Study Area. Evidence was 

found within both of these channel types where previously bypassed cutoff channels 

where becoming filled with sediment. The specific conditions varied within the Study 

Area. 

Based on the above technical findings, drainages with active surface flow were found 

within the Study Area with physical features that allow for the conveyance of surface 

flows. 

4.2.3 Landscape Features with a Recognizable OHWM

The desert dry washes with active flow were found to have identifiable features which 

represented the geographic reach of lateral surface water. These features included 

channels or beds with evidence of active flow and abutting banks which demarcated the 

lateral reach or extent of flow. Field indicators of the extent of active flow along the 

banks included water marks defined by linear deposits of fine grained sediment and/or 

minerals, bank scour, erosion, and/or shelving, and flow-deposited woody and soft tissue 

plant debris (Exhibit B). 

Based on the above technical findings, the active drainages, described in the above 

subsections, have recognizable landscape features from which the lateral extent of surface 

water flow can be geographically delineated. Field indicators of this surface water flow 

were used to identify the OHWM. Exhibit C shows representative active ephemeral 

drainages, as described in Section 3.5, Mapping. 

4.3 Field Indicators of Wetland Vegetation

Based on field observations within the Study Area a dominance of wetland plant species 

or hydrophytes was not found. Based on this result the criteria defined by current Corps’ 

regulatory guidance, including the 2008 Regional Supplement to the Corps of Engineers 

Wetland Delineation Manual: Arid West Region (Version 2.0) for wetland vegetation was 

not met. 

F-I.1-31
4.4. Presence of Wetland Vegetation within Natural and Manmade

Drainages

Based on field observations within the Study Area, a dominance of wetland plant species 

or hydrophytes was not found within natural or manmade drainages within the Study Area 

where active ephemeral drainages were found. 

F-I.1-32
5.0 AREAS POTENTIALLY SUBJECT TO JURISDICTION 

This section presents the findings of this delineation with respect to the identification and 

geographic extent of areas found that could potentially be regulated by the Corps and the 

EPA as wetlands or other waters of the United States under Section 404 of the Clean 

Water Act. 

5.1 Wetlands 

No areas meeting the Corps technical criteria for wetlands were identified within the 

Study Area. These findings are based on the absence of hydric soil, wetland hydrology, 

and / or wetland vegetation indicators as required by the Corps’ 1987 Manual, the Arid 

West Regional Supplement, guidance documents, and regulations. 

5.2 Other Waters of the U.S.

Ephemeral drainages or desert dry washes were found within the Study Area that meet the 

technical criteria to potentially be subject to CWA Section 404 jurisdiction as Other 

Waters of the United States (Exhibit C). This finding is based on the presence of an 

OHWM as required by Corps regulations. Length and width measurements of the 

ephemeral drainages found to contain an observable OHWM are provided by Exhibit B. 

F-I.1-33
6.0 CWA JURISDICTIONAL ANALYSIS

This section analyzes the potential for waters identified within the Study Area to 

constitute waters of the United States subject to jurisdiction under the CWA. Section 6.1 

provides an explanation of the jurisdictional determination process following EPA and 

Corps guidance. Section 6.2 defines the area to be analyzed (i.e., the Review Area). 

Section 6.3 analyzes the potential for waters of the United States to be present in the 

Review Area. Section 6.4 describes any jurisdictional and /or non-jurisdictional waters 

found. Section 6.5 summarizes the findings of this jurisdictional analysis. Section 6.6 is 

a disclaimer statement.

6.1 Regulatory Background

Beyond the Corps and EPA regulatory definitions of “waters of the United States” as 

described in Section 2.0, recent judicial decisions have further limited and refined the 

scope of CWA jurisdiction with regard to isolated waters and certain wetlands and nonnavigable tributaries. Two of these decisions are relevant to this jurisdictional analysis.

First, in Solid Waste Agency of Northern Cook County v. United States Army Corps of 

Engineers, No. 99-1178 (531 U. S. 159; [2001]) (SWANCC), both statutory and 

constitutional challenges were made to the assertion of CWA jurisdiction over isolated, 

non-navigable, intrastate waters solely on the basis that those waters were used as habitat 

by migratory birds. The U.S. Supreme Court in SWANCC rejected the “migratory bird 

rule,” and held that CWA jurisdiction does not exist over “isolated, non-navigable, 

intrastate waters” where there is no nexus to interstate or foreign commerce. 

Second, the U.S. Supreme Court’s plurality opinion in Rapanos v. United States, 547 

U.S. 715 (2006) (Rapanos), addressed jurisdiction over waters of the United States under 

Section 404 of the CWA. The concurring opinion by Justice Kennedy held in pertinent 

part that waters with a "significant nexus" to "navigable waters" are covered under the 

CWA. In response to Rapanos, on December 2, 2008, USEPA and the Corps issued 

guidance to EPA regions and Corps districts (the “Rapanos Guidance”) to address the 

jurisdictional scope of the CWA over certain types of waters (i.e., traditional navigable 

waters, wetlands adjacent to traditional navigable waters, non-navigable tributaries that 

are relatively permanent, and wetlands that directly abut tributaries). The Rapanos 

Guidance identifies which waters the agencies will categorically assert jurisdiction over 

and which will be subject to a case-by-case analysis based on the reasoning of the 

Rapanos opinions to identify whether the water has a “significant nexus” to a “traditional 

navigable water” (TNW). The Rapanos Guidance focuses only on those definitions of 

“waters of the United States” in 33 C.F.R. § 328.3(a)(1), (a)(5) and (a)(7).2

2 The Rapanos Guidance covers the following 33 C.F.R. § 328.3(a) definition of "waters of the United States":

Neither the 

Supreme Court nor the Rapanos Guidance draws a bright line with regard to the 

(a)(1) All waters which are currently used, or were used in the past, or may be susceptible to use in interstate or foreign 

commerce, including all waters which are subject to the ebb and flow of the tide; 

(a)(5) Tributaries of waters identified in paragraphs (a)(1)-(4) of this section; 

(a)(7) Wetlands adjacent to waters (other than waters that are themselves wetlands) identified in paragraphs (a)(1)-(6) 

of this section. 

F-I.1-34
geographic reach of jurisdiction, particularly in drainages where flows are ephemeral and 

where wetlands are adjacent to, but not directly abutting relatively permanent waters. The 

Rapanos Guidance provides in pertinent part the following: 

 The agencies will assert jurisdiction over non-navigable, not relatively 

permanent tributaries and their adjacent wetlands where such tributaries 

and wetlands have a significant nexus to a traditional navigable water. 

 A significant nexus analysis will assess the flow characteristics and 

functions of the tributary itself and the functions performed by any 

wetlands adjacent to the tributary to determine if they significantly affect 

the chemical, physical and biological integrity of downstream traditional 

navigable waters. 

 “Similarly situated” wetlands include all wetlands adjacent to the same 

tributary.

 Significant nexus includes consideration of hydrologic factors including 

the following: volume, duration, and frequency of flow, including 

consideration of certain physical characteristics of the tributary; 

proximity to the traditional navigable water; size of the watershed; 

average annual rainfall; average annual winter snow pack. 

 Significant nexus also includes consideration of ecologic factors 

including the following : potential of tributaries to carry pollutants and 

flood waters to traditional navigable waters; provision of aquatic habitat 

that supports a traditional navigable water; potential of wetlands to trap 

and filter pollutants or store flood waters; maintenance of water quality 

in traditional navigable waters. 

 The following geographic features generally are not jurisdictional 

waters: swales or erosional features (e.g. gullies, small washes 

characterized by low volume, infrequent, or short duration flow).... 

[Rapanos Guidance, at p. 8 (emphasis added)] 

According to the Rapanos Guidance, a significant nexus analysis “. . . will assess the flow 

characteristics and functions of the tributary itself, together with the functions performed 

by any wetlands adjacent to that tributary,” to determine if they significantly affect the 

chemical, physical and biological integrity of downstream traditional navigable waters.

(Rapanos Guidance, p. 8) The analysis will consider both hydrologic and ecologic 

factors. Hydrologic factors include volume, duration, and frequency of flow, proximity to 

the TNW, size of the watershed, and average annual rainfall. Ecologic factors include the 

potential for tributaries to carry pollutants and flood waters to TNWs or to provide 

aquatic habitat to support a TNW, and the potential for wetlands to trap and filter 

pollutants or store flood waters. The Guidance states (on p.10), “[w]here it is determined 

F-I.1-35
that a tributary and its adjacent wetlands collectively have a significant nexus with 

traditional navigable waters, the tributary and all of its adjacent wetlands are 

jurisdictional.” 

6.2 Review Area

For the purpose of this analysis, the Study Area used for the delineation process is also to 

be considered the Review Area. A Review Area as defined by the Rapanos Guidance is 

the area of interest for the verification of the location and extent of waters of the United 

States. Exhibit D presents a series of maps that show the Review Area relative to 

Badwater Basin. Exhibits D1 and D2 show USGS National Hydrography Dataset (NHD) 

flowlines and arrows that indicate the direction and route of surface water flow from the 

Review Area toward Badwater Basin; the NHD data are superposed respectively on an 

aerial photo and on a USGS topographic map. Exhibits D3 and D4 show the extent of the 

Review Area (also referred to as the Study Area). 

6.3 CWA Analysis 

Section 5.0 of this report discusses a number of active ephemeral drainages (locally 

known as desert dry washes) identified and delineated within the Study Area / Review 

Area that meet the technical criteria of “other waters” potentially subject to CWA 

jurisdiction. Maps showing the geographic extent of these drainages within the Review 

Area are presented in Exhibit D (Exhibits D1 – D4). The following discussion follows 

the Corps Approved Jurisdictional Determination Form developed following the Rapanos

decision. 

6.3.1 Are Jurisdictional Waters Present within the Study Area (Rapanos 

Guidance)? 

Table 6 provides a summary of the Rapanos Guidance process for determining 

jurisdiction over waters of the United States under Section 404 of the CWA. 

Table 6. Summary of Process for Determining Jurisdiction Over Waters of the U.S. Under Section 

404 of the Clean Water Act Following EPA and Corps Rapanos Guidance*

“Approved JD Form” Categories of 

Potential Waters of the U.S.**

Will Corps 

Categorically 

Assert 

Jurisdiction? 

Corps Will Assert Jurisdiction Based on a FactSpecific Analysis to Determine Whether Waters 

Identified Have a Significant Nexus With a TNW

Analysis Based 

on Significant 

Nexus Testing

Comments

1. Traditional navigable waters 

(TNWs), including territorial seas, 

and adjacent wetlands 

Yes Not Applicable 

(NA) NA

2. Wetlands adjacent to TNWs Yes NA NA

3. Relatively permanent waters 

(RPWs)3 that flow directly or Yes

indirectly into TNWs

NA NA

3

 Under the Corps / EPA Rapanos Guidance, a Relatively Permanent Water (RPW) is defined as a tributary that is not 

a TNW and that typically flows year-round or has continuous flow at least “seasonally” (e.g., typically 3 months).

F-I.1-36
Table 6. Summary of Process for Determining Jurisdiction Over Waters of the U.S. Under Section 

404 of the Clean Water Act Following EPA and Corps Rapanos Guidance*

“Approved JD Form” Categories of 

Potential Waters of the U.S.**

Will Corps 

Categorically 

Assert 

Jurisdiction? 

Corps Will Assert Jurisdiction Based on a FactSpecific Analysis to Determine Whether Waters 

Identified Have a Significant Nexus With a TNW

Analysis Based 

on Significant 

Nexus Testing

Comments

4. Non-RPWs that flow directly or 

indirectly into TNWs No Yes

Jurisdictional if the drainage flows 

directly or indirectly into a TNW and 

has a significant nexus with the TNW

5. Wetlands directly abutting RPWs 

that flow directly or indirectly into 

TNWs

Yes NA NA

6. Wetlands adjacent to but not 

directly abutting RPWs that flow 

directly or indirectly into TNWs

No Yes

Jurisdictional when considered in 

combination with the tributary to 

which they are adjacent and, with 

similarly situated adjacent wetlands, 

have a significant nexus with a TNW

7. Wetlands adjacent to non-RPWs 

that flow directly or indirectly into 

TNWs

No Yes

Jurisdictional when considered in 

combination with the tributary to 

which they are adjacent and, with 

similarly situated adjacent wetlands, 

have a significant nexus with a TNW

8. Impoundments of jurisdictional 

waters

Generally, 

impoundment of a 

water of the U.S. 

does not affect its 

jurisdictional 

status.

NA

Yes, if:

 Impoundment created from WOUS

 Water meets one of the above 

waters categories

 Water is isolated with a significant 

nexus to interstate or foreign 

commerce (to be elevated to Corps 

Headquarters for review consistent 

with Rapanos Guidance)

9. Isolated (interstate or intrastate) 

waters including isolated wetlands 

the use, degradation or destruction 

of which could affect interstate 

commerce

No

To be elevated to Corps Headquarters 

for review consistent with Rapanos 

Guidance

* U.S. Army Corps of Engineers. 2007. U.S. Army Corps of Engineers Jurisdictional Determination Form 

Instructional Guidebook. May 30.

** U.S. Army Corps of Engineers. 2007. Appendix B, Approved JD Form, Section II, in U.S. Army Corps of 

Engineers Jurisdictional Determination Form Instructional Guidebook. May 30.

As described in the technical findings of this report (Section 4.0), the active ephemeral 

drainages identified in the Review Area are not permanent or even seasonal, but rather 

flow or flood for few hours during heavy precipitation events. The climate data in 

Section 1.0 indicates that the Review Area receives an annual average rainfall amount of 

4 inches. Thus, these ephemeral drainages are non-Relatively Permanent Waters (nonRPWs). (A Relatively Permanent Water is defined in the Rapanos Guidance as a 

tributary that is not a TNW and that typically flows year-round or has continuous flow at 

least “seasonally” (e.g., typically 3 months). Representative drainages that flow to 

Badwater Basin are shown on Exhibits D3 and D4. These drainages (non-RPWs) are also

listed in the Exhibit B field data table. In addition, no areas were found within the 

F-I.1-37
Review Area that meet the Corps criteria for wetlands in the 1987 Corps of Engineers 

Wetlands Delineation Manual and/or the 2008 Arid West Supplement. 

Using the Rapanos Guidance analysis as summarized by Table 6, the non-RPWs were 

determined not to fall within any of the categories of potential waters of the U.S., as 

shown below in Table 7. 

Table 7. Summary of EPA and Corps Rapanos Analysis

“Approved JD Form” Categories of 

Potential Waters of the U.S.*

Wetlands 

Present? 

(acres)

Other Waters of 

the U.S 

Present? (acres)

Rationale For Determination if Waters 

in Review Area are Subject to Corps 

Jurisdiction under CWA Section 404

1. Traditional navigable waters 

(TNWs), including territorial seas No No Criteria for type of water not met; waters are non-RPWs. 

2. Wetlands adjacent to TNWs No No Criteria for type of water not met; no 

wetlands present within Review Area.

3. Relatively permanent waters 

(RPWs) that flow directly or 

indirectly into TNWs

No No

Criteria for type of water not met; waters 

are non-RPWs, but do not flow directly 

or indirectly into TNWs.

4. Non-RPWs that flow directly or 

indirectly into TNWs No No

Criteria for type of water not met; waters 

are non-RPWs that do not flow directly 

or indirectly into a TNW.

5. Wetlands directly abutting RPWs 

that flow directly or indirectly into 

TNWs

No No Criteria for type of water not met; no 

wetlands present within Review Area. 

6. Wetlands adjacent to but not 

directly abutting RPWs that flow 

directly or indirectly into TNWs

No No Criteria for type of water not met; no 

wetlands present within Review Area.

7. Wetlands adjacent to non-RPWs 

that flow directly or indirectly into 

TNWs

No No Criteria for type of water not met; no 

wetlands present within Review Area.

8. Impoundments of jurisdictional 

waters No No Criteria for type of water not met; waters are non-RPWs.

9. Isolated (interstate or intrastate) 

waters including isolated wetlands 

the use, degradation or destruction 

of which could affect interstate 

commerce

No No

Criteria for type of water not met. See 

Table 8 for interstate commerce analysis 

for the Review Area, the drainages 

connecting the Review Area to Badwater 

Basin, and Badwater Basin.

* U.S. Army Corps of Engineers. 2007. Appendix B, Approved JD Form, Section II, in U.S. Army Corps of Engineers 

Jurisdictional Determination Form Instructional Guidebook. May 30.

6.3.2 Are There Isolated Waters within the Study Area? 

When the non-RPWs identified within the Review Area flow, they flow toward the 

western boundary of Badwater Basin, an ephemeral dry lake with no outlet (Exhibit D). 

No substantial nexus to interstate or foreign commerce was found associated with the 

non-RPWs within the Review Area based on the following fact-specific analysis provided 

in Table 8 regarding whether the use, degradation, or destruction of the intrastate nonRPWs within the Review Area would affect interstate commerce. On the basis of HBG’s 

analysis, Badwater Basin was found to be: (1) a non-TNW, (2) an intrastate water located 

entirely within the state of California, and (3) an isolated basin with no hydrologic surface 

water outlet. No surface water connection to interstate or foreign commerce was found. 

F-I.1-38
Table 8. Interstate/Foreign Commerce Analysis

Factors Used to 

Determine Substantial 

Nexus to Interstate or 

Foreign Commerce

Could the Use, 

Degradation or 

Destruction of the 

Intrastate non-RPWs 

within the Review Area, 

Drainages Connecting 

the Review Area to 

Badwater Basin, or 

Badwater Basin Affect 

Interstate or Foreign 

Commerce?

Fact-Specific Analysis

Review Area Drainages Connecting the Review 

Area to Badwater Basin Badwater Basin

Waters which are or 

could be used by 

interstate or foreign 

travelers for recreational 

purposes.

No

Given the ephemeral as well as 

unpredictable nature of surface 

flows, no recreational use occurs 

that is surface water dependent. 

This was confirmed by site 

inspection, review of remote sensing 

imagery, and internet search.

Given the ephemeral as well as 

unpredictable nature of surface 

flows, no recreational use occurs that

is surface water dependent. This was 

confirmed by site inspection, review 

of remote sensing imagery, and 

internet search. 

Given the ephemeral as well as unpredictable 

nature of surface ponding, no recreational uses 

occur that are surface water dependent. This was 

confirmed by site inspection, review of remote 

sensing imagery, and internet search.

Waters from which fish 

or shellfish are or could 

be taken and sold in 

interstate or foreign 

commerce.

No

Given the ephemeral as well as 

unpredictable nature of surface 

flows, no fish or shellfish habitat is 

associated with the ephemeral 

drainages. This was confirmed by 

site inspection, review of remote 

sensing imagery, and internet search.

Given the ephemeral as well as 

unpredictable nature of surface 

flows, no fish or shellfish habitat is 

associated with the ephemeral 

drainages. This was confirmed by 

site inspection, review of remote 

sensing imagery and internet search.

Given the ephemeral as well as unpredictable 

nature of surface ponding, no fish or shellfish 

habitat is associated with this playa lake. This 

was confirmed by site inspection, review of 

remote sensing imagery, and internet search.

Waters which are or 

could be used for 

industrial purposes by 

industries in interstate 

commerce.

No

Given the ephemeral as well as 

unpredictable nature of surface 

flows, the non-RPWs are not used 

and could not be used for surfacewater-dependent industrial purposes, 

including, but not limited, to mineral 

extraction, power generation, and 

agricultural irrigation. This was 

confirmed by site inspection, review 

of remote sensing imagery, and 

internet search.

Given the ephemeral as well as 

unpredictable nature of surface 

flows, the non-RPWs are not used 

and could not be used for surfacewater-dependent industrial purposes, 

including, but not limited, to mineral 

extraction, power generation, and 

agricultural irrigation. This was 

confirmed by site inspection, review 

of remote sensing imagery, and 

internet search.

Given the ephemeral as well as unpredictable 

nature of surface ponding, the waters are not used 

and could not be used for surface-waterdependent industrial purposes, including but not 

limited to mineral extraction, power generation, 

and agricultural irrigation. This was confirmed 

by site inspection, review of remote sensing 

imagery, and internet search.

Waters which are 

interstate isolated waters. Not Applicable

Waters are intrastate non-RPWs 

found within the State of California

with no nexus to interstate or foreign 

commerce, as demonstrated by the 

above analysis.

Waters are intrastate non-RPWs 

found within the State of California 

with no nexus to interstate or foreign 

commerce, as demonstrated by the 

above analysis.

Badwater Basin is an intrastate water found 

within the State of California with no nexus to 

interstate or foreign commerce, as demonstrated 

by the above analysis. This isolated basin has no 

outlet (Exhibits D1 and D2).

Other factors Not Applicable No other factors known to occur. No other factors known to occur. No other factors known to occur.

F-I.1-39
6.4 Are Non-Jurisdictional Waters Present within the Study Area?

On the basis of the above analysis and findings, no areas were found within the Review 

Area, drainages connecting the Review Area to Badwater Basin, or Badwater Basin that 

meet the Corps criteria for wetlands defined in the 1987 Corps of Engineers Wetlands 

Delineation Manual and/or the 2008 Arid West Supplement. The above analysis also 

found that the Review Area and drainages connecting the Review Area to Badwater Basin 

contain non-RPWs that are isolated, non-navigable, and wholly intrastate waters with no 

substantial nexus to interstate or foreign commence. Furthermore, Badwater Basin itself 

is an isolated, non-navigable and wholly intrastate water with no substantial nexus to 

interstate or foreign commence. As required, as part of the determination process under 

the Rapanos Guidance, it should be noted that: 

1. Prior to the January 2001 Supreme Court decision in SWANCC, some portion of 

the non-RPWs in the Review Area would likely have been subject to CWA 

jurisdiction based on the then-existing Migratory Bird Rule (51 F.R. 41217), 

given the likely presence of migratory waterbirds during ephemeral ponding and 

the presence of a federal listed endangered species, the desert tortoise (Gopherus 

agassizii)

4

2. The waters are isolated with no significant nexus to interstate or foreign 

commerce and therefore no significant nexus standard analysis for connectivity to 

a TNW is required by the Rapanos Guidance as non-RPWs are not in a category 

of water requiring such analysis. 

, within the Review Area. 

6.5 Jurisdictional Analysis Summary

On the basis of the above analysis and as seen in the maps in Exhibit D and summarized 

in Table 9, the active ephemeral drainages (non-RPWs or desert dry washes) found within 

the (1) Review Area, (2) drainages connecting the Review Area to Badwater Basin, and 

(3) Badwater Basin would be considered non-jurisdictional under the CWA. The nonRPWs within the Review Area are not jurisdictional waters of the United States based on 

the facts that:

1. No wetlands were found with the Review Area as there were no areas that met the 

criteria in the 1987 Corps of Engineers Wetlands Delineation Manual and/or the 

2008 Arid West Supplement. 

2. The non-jurisdictional non-RPWs found are isolated waters with no substantial 

connection to interstate or foreign commerce. 

4

 Under the Migratory Bird Rule (51 F.R. 41217) the presence of or the potential for use by migratory 

birds and/ or Federally-listed species satisfies the determination requirements.

F-I.1-40
Table 9. Jurisdictional Analysis Summary

“Approved JD Form” 

Categories of Potential Waters 

of the U.S.*

Was 

Category of 

Waters 

Identified in 

Study 

Area?

Nexus to 

Interstate 

or Foreign 

Commerce?

Jurisdictional 

Water 

Found?

Non-Jurisdictional 

Water Found?

1. Traditional navigable water 

(TNW), including territorial 

seas 

No No No No

2. Wetlands adjacent to TNWs No No No No

3. Relatively permanent waters 

(RPWs) that flow directly or 

indirectly into TNWs

No No No No

4. Non-RPWs that flow directly 

or indirectly into TNWs No No No No

5. Wetlands directly abutting 

RPWs that flow directly or 

indirectly into TNWs

No No No No

6. Wetlands adjacent to but not 

directly abutting RPWs that 

flow directly or indirectly into 

TNWs

No No No No

7. Wetlands adjacent to nonRPWs that flow directly or 

indirectly into TNWs

No No No No

8. Impoundments of 

jurisdictional waters No No No No

9. Isolated (interstate or 

intrastate) waters including 

isolated wetlands the use, 

degradation or destruction of 

which could affect interstate 

commerce

No No No No

Waters** that are not one of the 

above nine categories of potential 

Waters of the U.S.

Yes No No

Yes

Review Area: 

Non-RPWs 

Drainages Connecting 

the Review Area to 

Badwater Basin: 

Non-RPWs

Badwater Basin:

Isolated Water

* U.S. Army Corps of Engineers. 2007. Appendix B, Approved JD Form, Section II, in U.S. Army Corps of 

Engineers Jurisdictional Determination Form Instructional Guidebook. May 30.

** Areas that meet the technical criteria for wetlands (collective presence of hydric soil, wetland hydrology 

and wetland vegetation indicators) or have an Ordinary High Water Mark (OHWM) but have no significant 

nexus to a TNW or connection to interstate commerce. 33 CFR 328.3(a)(3) states: “All other waters such as 

intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie 

potholes, wet meadows, playa lakes, or natural ponds, the use, degradation or destruction of which could affect 

interstate or foreign commerce including any such waters (i) which are or could be used by interstate or foreign 

travelers for recreational or other purposes; or (ii) From which fish or shellfish are or could be taken and sold 

in interstate or foreign commerce’ or (iii) Which are used or could be used for industrial purpose by industries 

in interstate commerce”

F-I.1-41
6.6 Disclaimer 

HBG has made a good-faith effort herein to thoroughly describe and document the 

presence of potential factors that the Corps may consider. Nevertheless, DXE reserves 

the right to challenge or seek revision to any areas over which the Corps may assert such 

jurisdiction, as the implementation of the Corps / EPA Rapanos Guidance is further 

clarified or altered through formal guidance, assertions or disclaimers of jurisdiction over 

other properties, court decisions, or other relevant actions.

F-I.1-42
7.0 References

Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. 

Technical Report Y-87-l, US Army Engineer Waterways Experiment Station, Vicksburg, 

Miss.

Field, J., & Pearthree, P. 1997. "Geomorphologic Flood-Hazard Assessment of Alluvial 

Fans and Piedmonts." Journal of Geoscience Education, Vol. 45, pp. 27 – 37. 

Hickman, J. (ed.). 1993. The Jepson Manual: Higher Plants of California. University of 

California Press, Berkeley, California.

Lichvar, R.W., D.C. Finnegan, and M.P. Ericsson. 2004. Using Hydrogeomorphic 

Surfaces for Delineating Floodplains: Black Water Creek Test Reach Within the Upper 

Puerco Watershed, Navajo Nation. ERDC/CRREL Technical Note 04-7. Hanover, NH: 

U.S. Army Engineer Research and Development Center, Cold Regions Research and 

Engineering Laboratory. November. 

Lichvar. R.W., and S.M. McColley. 2008. A Field Guide to the Identification of the 

Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United 

States, A Delineation Manual. ERDC/CRREL TR-08-12. Hanover, NH: U.S. Army 

Engineer Research and Development Center, Cold Regions Research and Engineering 

Laboratory. August. 

Munz, P.A. 1974. A Flora of Southern California. University of California Press, 

Berkeley, California.

Reed, P.B., Jr. 1988. National List of Plant Species that Occur in Wetlands: National 

Summary. U.S. Fish and Wildlife Service Biological Report 88(24). 244 pp. 

Santos, P.F., N. Z. Elkins, Y. Steinberger and W. G. Whitford. “A Comparison of 

Surface and Buried Larrea Tridentata Leaf Litter Decomposition in North American Hot 

Deserts.” Ecology, Vol. 65, No. 1 (Feb., 1984), pp. 278-284. 

Sawyer, J.O., and T. Keeler-Wolf. 1995. A Manual of California Vegetation. 

Sacramento, CA: California Native Plant Society. 471 p. 

Simley, J.D. and J.W.Carswell Jr. 2009. National Hydrography Dataset (NHD). The 

National Map - Hydrography: U.S. Geological Survey Fact Sheet 2009-3054, 4 p. 

Strojan, C.L, D. C. Randall and F. B. Turner. 1987. “Relationship of Leaf Litter 

Decomposition Rates to Rainfall in the Mojave Desert.” Ecology, Vol. 68, No. 3 (Jun., 

1987), pp. 741-744. 

F-I.1-43
U.S. Army Corps of Engineers. 2008. Regional Supplement to the Corps of Engineers 

Wetland Delineation Manual: Arid West Region (Version 2.0), ed. J. S. Wakeley, R. W. 

Lichvar, and C. V. Noble. ERDC/EL TR-08-28. Vicksburg, MS: U.S. Army Engineer 

Research and Development Center.

U.S. Army Corps of Engineers. 2009. Vegetation and Channel Morphology Responses 

to Ordinary High Water Discharge Events in Arid West Stream Channels, ed. R. 

Lichvar, D. Cate, C. Photos, L. Dixon, B. Allen, and J. Byersdorfer. ERDC/CRREL TR09-5. Hanover, NH: U.S. Army Engineer Research and Development Center, Cold 

Regions Research and Engineering Laboratory. May. 

U.S. Department of Agriculture, Natural Resources Conservation Service. 1986. Urban 

Hydrology for Small Watersheds. Technical Release 55 (TR-55). June. 

US Department of Agriculture, National Resources Conservation Service. 2009. Web 

Soil Survey: http://websoilsurvey.nrcs.usda.gov 

F-I.1-44
Exhibit A 

Figures

Figure 1 DesertXpress Project Alignment Alternatives

Figure 2 Location of Alignment Alternatives Within HUC-8 Watershed

Figure 3 Location of Study Area

Figure 4 Location of Study Area Within HUC-8 / HUC-12 Watersheds

Figures 5-12 Typical Examples of Field Indicators of Active Surface Water Flow and 

Ordinary High Water Marks Found Within Ephemeral Drainages 

Occurring Within the DesertXpress Project Study Area.

Figures 13-19 Examples of Drainages Found Within HUC-8 Watershed

F-I.1-45
Figure 1. DesertXpress Project Alignment Alternatives

Recent

SEGMENT 6B 

Alignment

Previous 

SEGMENT 7A and 7B

Previous

SEGMENT

Old Victorville Station

VICTORVILLE

BARSTOW

LAS VEGAS

NEVADA

CALIFORNIA

Yermo

Baker

Current Preferred

Victorville Station

Halloran Summit

Primm

Current Preferred

Las Vegas Station

Jean

Mountain Pass

SEGMENT

2 ALT C

SEGMENT 6 

ALT B

SEGMENT 4 ALT C

SEGMENT 5 ALT B

SEGMENT 1 

ALT B

SEGMENT 3 ALT B

Previous 

SEGMENT 7C

Previous SEGMENT Old 1

Previous

SEGMENT

Old 2

Previous 

SEGMENT 4A

Previous SEGMENT

6C Central A and B

Legend

Current Preferred Segments

SegName

SEGMENT 1 ALT B

SEGMENT 2 ALT C

SEGMENT 3 ALT B

SEGMENT 4 ALT C

SEGMENT 5 ALT B

SEGMENT 6 ALT B

Previous Segments

Label

Previous SEGMENT 4A

Previous SEGMENT 6C Central A and B

Previous SEGMENT 7A

Previous SEGMENT 7B

Previous SEGMENT 7C

Previous SEGMENT Old 1

Previous SEGMENT Old 2

Recent 6B Alignment

Current Preferred

Las Vegas Station

SEGMENT 6 ALT B

Previous 

SEGMENT 7C

Previous 

SEGMENT 7A and 7B

Recent 

SEGMENT 6B

Alignment

Previous

SEGMENT 6C

Central A and B

0 5 10 Miles

Previous SEGMENT Old 

Victorville Station

F-I.1-46
Yermo

Baker

Halloran Summit

Mountain 

Pass

SEGMENT 3 ALT B

Previous

Figure 2. Location Of Alignment Alternatives Within HUC-8 Watershed

Legend

HUC 8 Digit Subbasin

D e a t h V a l l e y -

W a t e r s h e d

0 5 10 15 20 25

Miles

L o w e r 

 A m a r g o s a

Death Valley-Lower Amargosa 

Watershed

F-I.1-47
Yermo

Baker

Halloran Summit

Mountain 

Pass

Previous

Figure 3. Location of Study Area

Legend

HUC 8 Digit Subbasin

D e a t h V a l l e y -

W a t e r s h e d

0 5 10 15 20 25

Miles

L o w e r 

 A m a r g o s a

Study Area

Death Valley-Lower Amargosa 

Watershed

F-I.1-48
Yermo

Baker

Halloran Summit

Mountain 

Pass

Previous

26

24

27

25

23

Figure 4. Location of Study Area Within HUC-8 / HUC-12 Watersheds

D e a t h V a l l e y -

W a t e r s h e d

0 5 10 15 20 25

Miles

L o w e r 

 A m a r g o s a

Legend

HUC 8 Digit Subbasin

23 - Halloran Summit

24 - Rock Tank

25 - Pachalka Spring-Kingston Wash

26 - Ord Tank

27 - Piute Valley

HUC 12 Digit Subwatershed

Death Valley-Lower Amargosa 

Watershed

Study Area

F-I.1-49
Exhibit A. Figure 5. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area.

F-I.1-50
Exhibit A. Figure 6. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area.

F-I.1-51
Exhibit A. Figure 7. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area.

F-I.1-52
Exhibit A. Figure 8. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area.

F-I.1-53
Exhibit A. Figure 9. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area. F-I.1-54
Exhibit A. Figure 10. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring 

within the DesertXpress Project Study Area.

F-I.1-55
Exhibit A. Figure 11. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area.

F-I.1-56
Exhibit A. Figure 12. Typical examples of field indicators of active surface water flow and Ordinary High Water Marks found within ephemerals drainages occurring within the 

DesertXpress Project Study Area.

F-I.1-57
Exhibit A. Figure 13. Ephemeral drainage within HUC 8 Death Valley Lower Amargosa / HUC 12 

Piute Valley Subwatershed

Exhibit A. Figure 14. Ephemeral drainage within HUC 8 Death Valley Lower Amargosa / HUC 12 

Piute Valley Subwatershed

F-I.1-58
Exhibit A. Figure 15. Ephemeral drainage within HUC 8 Death Valley Lower Amargosa / HUC 12 

Piute Valley Subwatershed

Exhibit A. Figure 16. Ephemeral drainage within HUC 8 Death Valley Lower Amargosa / HUC 12 

Piute Valley Subwatershed

F-I.1-59
Exhibit A. Figure 17. Manmade drainage connecting to road culvert within HUC 8 Death Valley 

Lower Amargosa / HUC 12 Piute Valley Subwatershed

Exhibit A. Figure 18. Manmade drainage connecting to road culvert within HUC 8 Death Valley 

Lower Amargosa / HUC 12 Piute Valley Subwatershed

F-I.1-60
Exhibit A. Figure 19. Ephemeral drainage within HUC 8 Death Valley Lower Amargosa / HUC 12 

Piute Valley Subwatershed

F-I.1-61
Exhibit B

Field Data

Exhibit B1 Required Corps Waters Data Summary Table

Exhibit B2 Field Data* 

(Exhibit B2 provided on attached CD in PDF format.)

F-I.1-62
Exhibit B1

Required Corps Waters Data Summary Table

F-I.1-63
2/14/2011 7:10 PM

Waters_Name

Cowardin_Code HGM_Code

Area (acres)

Linear (ft)

Waters Types

Latitude (dd nad83)

Longitude (dd nad83) Local_Waterway

D-23-2 R6 RIVERINE 0.050517 489.0 NRPW 35.406595 -115.782925 Halloran Summit D-23-4 R6 RIVERINE 0.103072 2244.9 NRPW 35.404845 -115.786272 Halloran Summit D-23-7 R6 RIVERINE 0.003747 81.6 NRPW 35.404067 -115.790363 Halloran Summit D-23-9 R6 RIVERINE 0.006892 150.1 NRPW 35.404000 -115.790650 Halloran Summit D-23-10 R6 RIVERINE 0.007989 174.0 NRPW 35.404026 -115.790103 Halloran Summit D-23-11 R6 RIVERINE 0.007534 218.8 NRPW 35.406436 -115.783398 Halloran Summit D-23-12 R6 RIVERINE 0.006017 262.1 NRPW 35.406301 -115.783152 Halloran Summit D-23-13 R6 RIVERINE 0.007163 312.0 NRPW 35.407191 -115.780687 Halloran Summit D-23-14 R6 RIVERINE 0.011033 480.6 NRPW 35.408771 -115.776383 Halloran Summit D-23-17 R6 RIVERINE 0.008136 354.4 NRPW 35.409559 -115.774347 Halloran Summit D-23-18 R6 RIVERINE 0.018223 793.8 NRPW 35.410955 -115.769995 Halloran Summit D-23-20 R6 RIVERINE 0.008710 379.4 NRPW 35.412004 -115.766846 Halloran Summit D-23-23 R6 RIVERINE 0.006476 282.1 NRPW 35.413143 -115.763782 Halloran Summit D-23-24 R6 RIVERINE 0.057932 504.7 NRPW 35.414762 -115.759039 Halloran Summit D-23-26 R6 RIVERINE 0.065689 476.9 NRPW 35.416842 -115.753578 Halloran Summit D-23-27 R6 RIVERINE 0.004614 201.0 NRPW 35.416969 -115.753350 Halloran Summit D-23-28 R6 RIVERINE 0.008567 373.2 NRPW 35.417086 -115.753094 Halloran Summit D-23-32 R6 RIVERINE 0.026680 387.4 NRPW 35.417808 -115.750624 Halloran Summit D-23-35 R6 RIVERINE 0.029883 433.9 NRPW 35.418951 -115.747540 Halloran Summit D-23-39 R6 RIVERINE 0.023485 341.0 NRPW 35.420459 -115.743362 Halloran Summit D-23-42 R6 RIVERINE 0.011470 333.1 NRPW 35.420630 -115.743592 Halloran Summit D-23-45 R6 RIVERINE 0.067284 418.7 NRPW 35.421347 -115.740829 Halloran Summit D-23-49 R6 RIVERINE 0.025436 1108.0 NRPW 35.416254 -115.754798 Halloran Summit D-23-50 R6 RIVERINE 0.003021 131.6 NRPW 35.417368 -115.752623 Halloran Summit D-23-51 R6 RIVERINE 0.004022 116.8 NRPW 35.417346 -115.752890 Halloran Summit D-24-2 R6 RIVERINE 0.049954 435.2 NRPW 35.423378 -115.734832 Rock Tank D-24-3 R6 RIVERINE 0.047050 409.9 NRPW 35.424500 -115.731733 Rock Tank D-24-4 R6 RIVERINE 0.037071 403.7 NRPW 35.425835 -115.728196 Rock Tank D-24-6 R6 RIVERINE 0.036896 401.8 NRPW 35.427002 -115.724662 Rock Tank D-24-7 R6 RIVERINE 0.041304 449.8 NRPW 35.428299 -115.721549 Rock Tank D-24-8 R6 RIVERINE 0.085090 741.3 NRPW 35.429419 -115.717545 Rock Tank D-24-11 R6 RIVERINE 0.048176 333.1 NRPW 35.430128 -115.715903 Rock Tank D-24-19 R6 RIVERINE 1.085537 788.1 NRPW 35.433342 -115.707693 Rock Tank D-24-27 R6 RIVERINE 0.130450 710.3 NRPW 35.434921 -115.703878 Rock Tank D-24-28 R6 RIVERINE 0.006360 184.7 NRPW 35.434979 -115.704028 Rock Tank D-24-29 R6 RIVERINE 0.011109 322.6 NRPW 35.435008 -115.703669 Rock Tank Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Death Valley-Lower Amargosa, DesertXpress Project

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Waters_Name

Cowardin_Code HGM_Code

Area (acres)

Linear (ft)

Waters Types

Latitude (dd nad83)

Longitude (dd nad83) Local_Waterway

Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Death Valley-Lower Amargosa, DesertXpress Project

D-24-30 R6 RIVERINE 0.005362 155.7 NRPW 35.435733 -115.703499 Rock Tank D-25-11 R6 RIVERINE 0.417626 546.3 NRPW 35.437635 -115.695430 Pachalka Spring-Kingston WasD-25-21 R6 RIVERINE 0.004800 418.2 NRPW 35.439435 -115.689397 Pachalka Spring-Kingston WasD-25-7 R6 RIVERINE 0.008366 520.6 NRPW 35.438486 -115.692918 Pachalka Spring-Kingston WasD-26-1 R6 RIVERINE 0.099210 270.1 NRPW 35.441309 -115.683918 Ord Tank D-26-3 R6 RIVERINE 0.003733 162.6 NRPW 35.441378 -115.683246 Ord Tank D-27-1 R6 RIVERINE 0.082090 586.2 NRPW 35.442760 -115.680165 Piute Valley D-27-21 R6 RIVERINE 0.012116 219.9 NRPW 35.445740 -115.671739 Piute Valley D-27-22 R6 RIVERINE 0.019669 357.0 NRPW 35.445822 -115.671189 Piute Valley D-27-23 R6 RIVERINE 0.005758 104.5 NRPW 35.445940 -115.670943 Piute Valley D-27-38 R6 RIVERINE 0.013041 236.7 NRPW 35.446847 -115.669222 Piute Valley D-27-45 R6 RIVERINE 0.028645 519.9 NRPW 35.447471 -115.666753 Piute Valley D-27-46 R6 RIVERINE 0.014733 267.4 NRPW 35.447546 -115.666880 Piute Valley D-27-47 R6 RIVERINE 0.020149 365.7 NRPW 35.450340 -115.658814 Piute Valley D-27-48 R6 RIVERINE 0.032722 593.9 NRPW 35.453634 -115.649205 Piute Valley D-27-50 R6 RIVERINE 3.417980 13535.2 NRPW 35.452052 -115.652943 Piute Valley D-27-56 R6 RIVERINE 0.016843 305.7 NRPW 35.458286 -115.636159 Piute Valley D-27-58 R6 RIVERINE 0.027019 490.4 NRPW 35.457910 -115.637210 Piute Valley D-27-60 R6 RIVERINE 0.039135 710.3 NRPW 35.457053 -115.639481 Piute Valley D-27-68 R6 RIVERINE 0.073433 285.6 NRPW 35.466406 -115.613079 Piute Valley D-27-69 R6 RIVERINE 0.077720 305.0 NRPW 35.468121 -115.607698 Piute Valley D-27-70 R6 RIVERINE 0.008116 147.3 NRPW 35.468406 -115.607458 Piute Valley D-27-71 R6 RIVERINE 0.125372 492.0 NRPW 35.468371 -115.607053 Piute Valley D-27-80 R6 RIVERINE 0.022623 410.6 NRPW 35.473306 -115.593187 Piute Valley D-27-83 R6 RIVERINE 0.092704 363.8 NRPW 35.474268 -115.589488 Piute Valley D-27-84 R6 RIVERINE 0.005686 103.2 NRPW 35.474399 -115.589678 Piute Valley D-27-86 R6 RIVERINE 0.404324 1586.7 NRPW 35.474784 -115.585377 Piute Valley D-27-87 R6 RIVERINE 0.395941 1553.8 NRPW 35.475499 -115.581241 Piute Valley D-27-88 R6 RIVERINE 0.036134 141.8 NRPW 35.475824 -115.580104 Piute Valley D-27-89 R6 RIVERINE 0.176417 883.3 NRPW 35.475044 -115.583209 Piute Valley D-27-92 R6 RIVERINE 0.090360 354.6 NRPW 35.475374 -115.583088 Piute Valley D-27-121 R6 RIVERINE 0.224153 513.9 NRPW 35.475765 -115.570119 Piute Valley D-27-124 R6 RIVERINE 0.020253 367.6 NRPW 35.474341 -115.563446 Piute Valley D-27-127 R6 RIVERINE 0.191982 753.4 NRPW 35.474122 -115.563372 Piute Valley D-27-130 R6 RIVERINE 0.084566 1674.4 NRPW 35.473446 -115.561957 Piute Valley D-27-134 R6 RIVERINE 0.037278 676.6 NRPW 35.472335 -115.556231 Piute Valley 

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Waters_Name

Cowardin_Code HGM_Code

Area (acres)

Linear (ft)

Waters Types

Latitude (dd nad83)

Longitude (dd nad83) Local_Waterway

Exhibit B1. Study Area Field Data for Areas Potentially Subject to Corps Jurisdiction, HUC-8 Death Valley-Lower Amargosa, DesertXpress Project

D-27-135 R6 RIVERINE 0.010986 199.4 NRPW 35.472484 -115.555981 Piute Valley D-27-136 R6 RIVERINE 0.007741 140.5 NRPW 35.472512 -115.556233 Piute Valley D-27-137 R6 RIVERINE 0.036545 663.3 NRPW 35.471430 -115.553736 Piute Valley D-27-138 R6 RIVERINE 0.018353 333.1 NRPW 35.471554 -115.552679 Piute Valley D-27-139 R6 RIVERINE 0.007614 138.2 NRPW 35.471737 -115.552283 Piute Valley D-27-140 R6 RIVERINE 0.049609 900.4 NRPW 35.471175 -115.552115 Piute Valley D-27-141 R6 RIVERINE 0.162190 1177.5 NRPW 35.470665 -115.548718 Piute Valley D-27-142 R6 RIVERINE 0.045173 231.5 NRPW 35.471240 -115.550452 Piute Valley D-27-144 R6 RIVERINE 0.020028 363.5 NRPW 35.470989 -115.549190 Piute Valley D-27-145 R6 RIVERINE 0.014573 317.4 NRPW 35.470659 -115.546574 Piute Valley D-27-156 R6 RIVERINE 0.005464 95.2 NRPW 35.466127 -115.613253 Piute Valley D-27-157 R6 RIVERINE 0.143611 568.7 NRPW 35.447192 -115.675613 Piute Valley D-27-158 R6 RIVERINE 0.094649 473.9 NRPW 35.446740 -115.675706 Piute Valley D-27-159 R6 RIVERINE 0.026992 489.9 NRPW 35.448417 -115.664052 Piute Valley D-27-160 R6 RIVERINE 0.013647 247.7 NRPW 35.448970 -115.663204 Piute Valley D-27-161 R6 RIVERINE 0.011774 213.7 NRPW 35.454406 -115.647608 Piute Valley D-27-162 R6 RIVERINE 0.080193 1455.5 NRPW 35.455119 -115.645362 Piute Valley D-27-163 R6 RIVERINE 0.051945 942.8 NRPW 35.455604 -115.643338 Piute Valley D-27-164 R6 RIVERINE 0.296584 5383.0 NRPW 35.464012 -115.619006 Piute Valley D-27-165 R6 RIVERINE 0.116193 2108.9 NRPW 35.475678 -115.575419 Piute Valley D-27-166 R6 RIVERINE 0.013163 238.9 NRPW 35.475790 -115.570716 Piute Valley D-27-167 R6 RIVERINE 0.010119 220.4 NRPW 35.443003 -115.679739 Piute Valley D-27-170 R6 RIVERINE 0.005344 97.0 NRPW 35.469902 -115.603478 Piute Valley D-27-171 R6 RIVERINE 0.008066 146.4 NRPW 35.470154 -115.602173 Piute Valley D-27-172 R6 RIVERINE 0.163774 2972.5 NRPW 35.469958 -115.602706 Piute Valley D-27-173 R6 RIVERINE 0.000996 21.7 NRPW 35.442873 -115.679833 Piute Valley 

Totals: 9.903974 67350.5

J:\DesertXpress\Revised JD Spreadsheets 2-2-11\GWB Formatted 02 14 11\Death_Valley-Lower_Amargosa 110214gwb Death_Valley

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Exhibit B2

Field Data

(See attached CD in PDF format.)

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Exhibit B2 

DesertXpress Field Data

For

Death Valley-Lower Amargosa Watershed

(HUC 18090203) 

HBG 

Watershed 

Number

HUC 12 Watershed Name

HBG 

Field 

Data

ICF Jones 

& Stokes 

Field Data

Comments

23 Halloran Summit Yes Yes

24 Rock Tank Yes Yes

25 Pachalka Spring-Kingston 

Wash Yes No

26 Ord Tank Yes Yes

27 Piute Valley Yes Yes

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Exhibit B2 

DesertXpress Field Data

For

Death Valley-Lower Amargosa Watershed

(HUC 18090203) 

HBG 

Watershed 

Number

HUC 12 Watershed Name

HBG 

Field 

Data

ICF Jones 

& Stokes 

Field Data

Comments

23 Halloran Summit Yes Yes

24 Rock Tank Yes Yes

25 Pachalka Spring-Kingston 

Wash Yes No

26 Ord Tank Yes Yes

27 Piute Valley Yes Yes

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Exhibit B2 

DesertXpress Field Data

For

Death Valley-Lower Amargosa Watershed

(HUC 18090203) 

HBG 

Watershed 

Number

HUC 12 Watershed Name

HBG 

Field 

Data

ICF Jones 

& Stokes 

Field Data

Comments

23 Halloran Summit Yes Yes

24 Rock Tank Yes Yes

25 Pachalka Spring-Kingston 

Wash Yes No

26 Ord Tank Yes Yes

27 Piute Valley Yes Yes

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Exhibit B2 

DesertXpress Field Data

For

Death Valley-Lower Amargosa Watershed

(HUC 18090203) 

HBG 

Watershed 

Number

HUC 12 Watershed Name

HBG 

Field 

Data

ICF Jones 

& Stokes 

Field Data

Comments

23 Halloran Summit Yes Yes

24 Rock Tank Yes Yes

25 Pachalka Spring-Kingston 

Wash Yes No

26 Ord Tank Yes Yes

27 Piute Valley Yes Yes

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Exhibit B2 

DesertXpress Field Data

For

Death Valley-Lower Amargosa Watershed

(HUC 18090203) 

HBG 

Watershed 

Number

HUC 12 Watershed Name

HBG 

Field 

Data

ICF Jones 

& Stokes 

Field Data

Comments

23 Halloran Summit Yes Yes

24 Rock Tank Yes Yes

25 Pachalka Spring-Kingston 

Wash Yes No

26 Ord Tank Yes Yes

27 Piute Valley Yes Yes

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Exhibit C

Representative Areas Potentially Excluded from 

Corps Jurisdiction Based on Corps-EPA Rapanos 

Guidance, DesertXpress Project, HUC 8 Death 

Valley-Lower Amargosa Watershed Draining to 

Badwater Basin

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Exhibit D

Hydrology Maps for CWA Jurisdictional Analysis

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